On our way through the nutrition alphabet, it's time for G...how could it not be gluten? You can hardly have a conversation (here on the diet-conscious West Coast at least!) without the word popping up.
You know, in my education, I actually didn't learn a lot about Celiac Disease and gluten. It was only when I started my career that I became immersed in the world of the gluten free and nowadays, gluten free advocates are multiplying like rabbits. As a dietitian, it is impossible to ignore...and for the public, an important topic on which to set a few things straight. So let's start with a simple definition.
What is gluten?
Gluten refers to a family of storage proteins, also called prolamins, that are found in wheat, barley and rye and all grains related to (and commonly contaminated with) them. Spelt and Kamut contain gluten. Most commercial oats are cross-contaminated with gluten. For this reason, wheat free and gluten free do not mean the same thing. This is an important fact to remember because many I see are confused by this. Since gluten is a protein found in wheat AND other grains, all gluten free foods will be also free of wheat but since gluten is found in other grains, a wheat free food might still have gluten.
Is gluten bad for me?
It depends on who you ask. Us darned health professionals have differing views on this question, based on our interpretation of the research available. In conventional medical thinking, only those of us with Celiac Disease or non-Celiac gluten sensitivity need to avoid gluten. According to best estimates, 1% of us in North America have Celiac Disease, an auto-immune disease that causes the body to attack itself when gluten is ingested. Celiac Disease is NOT an allergy to gluten. Gluten is the trigger that activates the disease process in those who have it.
Dr Alessio Fasano, of the Cleveland Clinic, also estimates that a further 6% of us have non-Celiac gluten sensitivity, which is non-immune mediated yet still causes health concerns when gluten is consumed. Doing the quick math, that should leave 93% of us who can safely and healthfully consume gluten. However, advocates of many popular diets including the Wheat Belly Diet and the Paleo Diet, believe that all of us should stop consuming gluten. There, the research becomes a little more fuzzy.
We'll get further into the question of whether we should avoid gluten in the next instalment...
Showing posts with label nutrition ABCs. Show all posts
Showing posts with label nutrition ABCs. Show all posts
Sunday, June 3, 2012
Friday, May 11, 2012
Nutrition ABCs...F is for Fat (Part Two)
My first post on fat described what fat actually is and why we need it. Today, let's talk practicalities - which fats you want more of and what food choices you can make to get you there. As promised, here are the good, the bad and the ugly - where fats are concerned.
Good Fats
Good Fats
Mono-unsaturated fats
Mono-unsaturated fats are found in most plant-based oils such as extra virgin olive oil, nuts, seeds and avocados. They do not increase your risk of disease although eating too much of them, like any fat, might add a little padding to your bottom line. Replacing saturated fats or processed carbohydrates with mono-unsaturated fats can help lower cholesterol and risk of heart disease. This type of fat is the mainstay of your healthy fat menu.
What does this mean for you? Use extra-virgin olive oil as your main culinary fat. Don't pour with abandon - you really only need about 1/2 - 1 tsp of oil per person when you cook. Enjoy avocado, raw nuts, seeds and nut butters more often as these whole food sources of fat come complexed with many other nutrients like fibre.
Poly-unsaturated fats
Poly-unsaturated fats are also found in plant-based oils, usually the nuts and seeds. Soy beans, dark green leafy veggies, algae and cold water, oily fish are also rich in poly-unsaturated fats. There are many different poly-unsaturated fatty acids but the ones with all the hoopla are the omega 3s and omega 6s. Essentially, they are twins - one is kind of evil, one is nicer. Both are necessary to your health. It is when these two are out of balance that our health suffers. Here's why:
Omega 3 fatty acids are precursors for molecules that are generally anti-inflammatory. Omega 6 fatty acids, with few exceptions, are precursors for molecules that are pro-inflammatory. The jury is still out on the "perfect" ratio of omega 3s to omega 6s. However, it should look a lot closer to 1:2 or 1:4 rather than the 1:10+ typically seen in the standard American diet. How did this come to be? Well, you see the list above of omega 3 food sources? Not exactly on the menu at Taco Bell. These are very healthy foods that just aren't that common for many people. What is common is fast food, "convenience" foods and tons of processed flour and sugar-rich baked goods that also feature tons of cheap, omega 6-laden fat like soy and corn oil.
What does this mean for you? Eat fewer processed and fast foods; rid your cabinet of margarine and cooking oils (except olive oil) to reduce your intake of omega 6s. If you are allergic to dairy or vegan, consider using an organic coconut oil-based spread but use it sparingly. Increase your intake of oily fish (if you eat fish) like herring, sablefish and salmon; eat more flax, hemp, pumpkin and chia seeds and dark green leafy veg to increase your omega 3 intake.
If you choose to supplement, don't pay for a 3-6-9 supplement; you get plenty of 6 (most foods) and 9 (olive oil!) already. Don't buy into the marketing. Look for EPA and DHA in your supplement, as these are the omega 3 forms that are most rigorously tested in a clinical setting. I like the new algae-based supplements from a sustainability standpoint. They don't contain EPA but the body can inter-convert DHA to EPA and they usually contain oils that can theoretically increase EPA in the body.
If you choose to supplement, don't pay for a 3-6-9 supplement; you get plenty of 6 (most foods) and 9 (olive oil!) already. Don't buy into the marketing. Look for EPA and DHA in your supplement, as these are the omega 3 forms that are most rigorously tested in a clinical setting. I like the new algae-based supplements from a sustainability standpoint. They don't contain EPA but the body can inter-convert DHA to EPA and they usually contain oils that can theoretically increase EPA in the body.
Less Good...and sometimes bad
Saturated Fats
Saturated fats come mostly from meat and dairy and can also be found in tropical oils - such as palm and coconut. We used to think that saturated fat was terrible for you and then the team at Harvard School of Public Health published a review article that challenged this thinking. We come back to these kinds of contradictions time and time again in nutrition science. Why? In my opinion, it is because we don't eat tubs of saturated fat. We eat food. And each food is a complex substance filled with different nutrients and co-factors that we still don't fully understand. And we eat these foods in the context of diets and lifestyles that change their impact.
So what is the current thinking on saturated fat? Generally speaking, it falls into the "a little is fine, too much is bad" category. We need some saturated fat in our diets. However, the foods and eating patterns associated with a higher intake of saturated fat (meat, dairy, fast food...) are the same ones that will point us in the direction of less healthy choices and risk for obesity and chronic disease. So look to minimize your intake of saturated fats. And what about coconut oil? Don't believe the hype - it will not cure your cancer or help you to lose 10 lbs without dieting. However, the "new" coconut oil is far less processed than the stuff that used to fill processed food in the eighties. It appears that plant-based saturated fats won't raise blood cholesterol as much as animal-based ones. But they still can't touch the health benefits of mono-unsaturated or omega 3 fats.
So what is the current thinking on saturated fat? Generally speaking, it falls into the "a little is fine, too much is bad" category. We need some saturated fat in our diets. However, the foods and eating patterns associated with a higher intake of saturated fat (meat, dairy, fast food...) are the same ones that will point us in the direction of less healthy choices and risk for obesity and chronic disease. So look to minimize your intake of saturated fats. And what about coconut oil? Don't believe the hype - it will not cure your cancer or help you to lose 10 lbs without dieting. However, the "new" coconut oil is far less processed than the stuff that used to fill processed food in the eighties. It appears that plant-based saturated fats won't raise blood cholesterol as much as animal-based ones. But they still can't touch the health benefits of mono-unsaturated or omega 3 fats.
What does this mean for you? Eat a modest amount of lean meats such as poultry and seafood and just a bit of red meat (if you eat meat!). Remember that meat servings don't need to be bigger than a deck of cards. Skim the fat from milk and yogurt; eat smaller portions of cheese - don't just slather everything with it. Save good quality (preferably organic) butter for occasional baking. Enjoy good quality coconut oil in recipes if you like but don't start eating it with abandon. Saturated fats are not something you need to actively seek out...there is a small amount of saturated fat in almost every other fat source we consume.
Down-Right Ugly
Industrial trans fats
A trans fat is made in two ways: the first, due to the miracle of a cow's many stomachs; the second, as a marvel of modern science. The first way does not appear to cause any harm and may even have some benefit. The second needs to be eradicated from our food supply. It is highly inflammatory; it raises our bad cholesterol and even worse...lowers our good cholesterol. It exists for the sole purpose of extending the shelf life (and profit margins) of foods we shouldn't be eating in the first place. I won't bother with much of a debate. These things are terrible.
What does this mean for you? Beware the "trans fat free" food. If a food contains less than 0.5 grams of trans fat per serving, it can be labelled trans fat free. However, if you eat 6 cookies with 0.3 grams of trans fats each, you have just consumed 1.8 grams. Doesn't sound like much, but it is essentially your "safe" daily limit for trans fats. Instead, avoid fried foods in restaurants and fast food outlets as these are most at risk for being filled with trans fats. Ditto for cheap baked goods like cookies, muffins and pastries. Read ingredients lists: if you see the words shortening, margarine or hydrogenated fat - take a pass.
Have a question about fats? Let me know!
What does this mean for you? Beware the "trans fat free" food. If a food contains less than 0.5 grams of trans fat per serving, it can be labelled trans fat free. However, if you eat 6 cookies with 0.3 grams of trans fats each, you have just consumed 1.8 grams. Doesn't sound like much, but it is essentially your "safe" daily limit for trans fats. Instead, avoid fried foods in restaurants and fast food outlets as these are most at risk for being filled with trans fats. Ditto for cheap baked goods like cookies, muffins and pastries. Read ingredients lists: if you see the words shortening, margarine or hydrogenated fat - take a pass.
Have a question about fats? Let me know!
Sunday, May 6, 2012
Nutrition ABCs...F is for Fat (Part One)
Fat. We love to eat it. We hate it on our backsides. We have tried low fat...and gotten even fatter. We demonized saturated fat and then questioned whether it is really all that bad for us. We have gone gaga for omega 3s but only if they are in the "right" ratio to omega 6s - what is the right ratio, anyway?
Need the low down on this much-discussed macronutrient? Read on, my friends...read on.
Let's start with the basics. What is fat?
A dietary fat is composed of a glycerol backbone and 3 fatty acid tails. The type of tails determines the structure and function of the fat. If the fatty acids are saturated, they line up nice and snug and are solid at room temperature, like butter and coconut oil. If the fatty acids are missing one little hydrogen molecule, it is called a mono-unsaturated fat. At room temperature, these are liquid fatty acids such as oleic acid, the primary component of olive oil. If there is more than one hydrogen molecule missing, the liquid fat is called poly-unsaturated. These are your omegas. These fats are so "fluid" and flexible that they stay liquid even when cold. Think of flax oil - it doesn't turn solid in the fridge like olive oil does.
So in my next post, we'll break it down and talk the good, the bad and the ugly.
Need the low down on this much-discussed macronutrient? Read on, my friends...read on.
Let's start with the basics. What is fat?
A dietary fat is composed of a glycerol backbone and 3 fatty acid tails. The type of tails determines the structure and function of the fat. If the fatty acids are saturated, they line up nice and snug and are solid at room temperature, like butter and coconut oil. If the fatty acids are missing one little hydrogen molecule, it is called a mono-unsaturated fat. At room temperature, these are liquid fatty acids such as oleic acid, the primary component of olive oil. If there is more than one hydrogen molecule missing, the liquid fat is called poly-unsaturated. These are your omegas. These fats are so "fluid" and flexible that they stay liquid even when cold. Think of flax oil - it doesn't turn solid in the fridge like olive oil does.
What does fat do in our bodies?
A dietary fat has 9 calories per gram, compared to 4 calories per gram for protein or carbohydrate. It is a concentrated source of energy. When we eat fats, they are digested into fatty acid components so they can be absorbed into the body. Once across the gut, they get repackaged into a molecule called a chylomicron that is transported to the bloodstream so the fatty acids can be carried to cells that need them for energy. And if the cells don't need that energy...the fatty acids travel to fat cells for storage.
We need some fat to help us absorb the fat soluble vitamins A,D,E + K and some of the fat-soluble phytochemicals, such as lycopene in tomatoes. Fatty acids also carry flavour so that we enjoy food more. Fatty acids become incorporated into our cell membranes, which is essentially the bag that holds the cell contents. Eat more saturated fats and your cell membranes will be more saturated. Eat more omega 3 fats and your cells will contain more omega 3s. Fatty acids are also the starting material for cell signalling molecules that can cause muscle contractions or even influence the immune system.
While fat can contribute to weight gain when consumed in excess, it is really the quality of fats that matter most - not the quantity - when we are talking about good health.
So in my next post, we'll break it down and talk the good, the bad and the ugly.
Thursday, March 22, 2012
Nutrition ABCS...Eggs
There are some nutrition questions that never fade...like whether or not eggs are good for you. I am here to set the record straight (well, let's be honest...you might find some other opinions and then you will just have to decide for yourself who to believe.). I think eggs, if you are of the animal product eating sort, are fantastic.
Of all the animal products you could choose, eggs are pretty light on the environment. And if you stop being so stingy and spend a bit more for eggs from a farm with humane animal husbandry practices, you can keep the chickens happy while they are on this earth producing food for you. I can't stress this enough...do not buy scary national brand, "where did these eggs come from?" eggs. Factory farming is horrific. Don't add to the demand for these kind of eggs.
So why do I think eggs are good for you? For starters, eggs really got a bad wrap when we decided that dietary cholesterol was the primary kick start to high blood cholesterol, a risk factor for heart disease. So the nutrition army rallied its troops to get you to stop eating eggs. Times have changed. So if you are still an egg-avoider, time to reconsider this humble breakfast staple.
Eggs are inexpensive and convenient sources of protein; in a world where we rely almost exclusively on inexpensive and convenient sources of white flour and sugar, eggs provide a break (pun intended) from the everyday. A large egg has just 70 calories for 6 grams of protein and a host of nutrients for better health: anti-oxidant lutein and zeaxanthin for your eyes, folate for a healthy nervous system, vitamin A for your skin and immune health and antioxidant selenium. They provide easily assimilated protein and are super versatile.
Just a few of my favourite egg-eating ways...
- Hard-boiled and stashed in the fridge for meals and snacks on the go
- Tossed with leeks, mushrooms and spinach for a quick dinner fritatta
- Deviled with dijon mustard and a bit of freshly grated horseradish
- In the classic tortilla espanola
- Gently fried and layered on sprouted grain toast with fresh chevre, sliced tomato and a bit of pesto
- Chopped up on a salad for some energy-boosting protein to go with all those glorious greens
So if you are about to embark on an egg-siting new journey, how much is too much? Don't go all Atkins on me; you've gotta keep it balanced. Research suggests that an egg a day won't raise your risk of heart disease. However, another way to look at eggs is through your nutrition "budget". If you don't have heart disease consider eggs a "serving" of saturated fat and cholesterol. If you generally keep all your dairy skim, don't consume too many saturated fats from coconut, meat or butter, you have a bit more room to enjoy eggs as you like them. However, if you drink cream in your coffee and slather butter on your bread as you scarf down steak...well, we should really talk. And you should probably stick to egg white omelets.
I am not one to take chances with your health: if you have heart disease or high cholesterol, you have to keep your dietary cholesterol to under 200 mg a day. A large egg has 180, so there you go. You have to decide if the egg is worth the spend for you because you get your egg or your small piece of steak plus a bit of butter for that potato. You don't get both.
Of all the animal products you could choose, eggs are pretty light on the environment. And if you stop being so stingy and spend a bit more for eggs from a farm with humane animal husbandry practices, you can keep the chickens happy while they are on this earth producing food for you. I can't stress this enough...do not buy scary national brand, "where did these eggs come from?" eggs. Factory farming is horrific. Don't add to the demand for these kind of eggs.
So why do I think eggs are good for you? For starters, eggs really got a bad wrap when we decided that dietary cholesterol was the primary kick start to high blood cholesterol, a risk factor for heart disease. So the nutrition army rallied its troops to get you to stop eating eggs. Times have changed. So if you are still an egg-avoider, time to reconsider this humble breakfast staple.
Eggs are inexpensive and convenient sources of protein; in a world where we rely almost exclusively on inexpensive and convenient sources of white flour and sugar, eggs provide a break (pun intended) from the everyday. A large egg has just 70 calories for 6 grams of protein and a host of nutrients for better health: anti-oxidant lutein and zeaxanthin for your eyes, folate for a healthy nervous system, vitamin A for your skin and immune health and antioxidant selenium. They provide easily assimilated protein and are super versatile.
Just a few of my favourite egg-eating ways...
- Hard-boiled and stashed in the fridge for meals and snacks on the go
- Tossed with leeks, mushrooms and spinach for a quick dinner fritatta
- Deviled with dijon mustard and a bit of freshly grated horseradish
- In the classic tortilla espanola
- Gently fried and layered on sprouted grain toast with fresh chevre, sliced tomato and a bit of pesto
- Chopped up on a salad for some energy-boosting protein to go with all those glorious greens
So if you are about to embark on an egg-siting new journey, how much is too much? Don't go all Atkins on me; you've gotta keep it balanced. Research suggests that an egg a day won't raise your risk of heart disease. However, another way to look at eggs is through your nutrition "budget". If you don't have heart disease consider eggs a "serving" of saturated fat and cholesterol. If you generally keep all your dairy skim, don't consume too many saturated fats from coconut, meat or butter, you have a bit more room to enjoy eggs as you like them. However, if you drink cream in your coffee and slather butter on your bread as you scarf down steak...well, we should really talk. And you should probably stick to egg white omelets.
I am not one to take chances with your health: if you have heart disease or high cholesterol, you have to keep your dietary cholesterol to under 200 mg a day. A large egg has 180, so there you go. You have to decide if the egg is worth the spend for you because you get your egg or your small piece of steak plus a bit of butter for that potato. You don't get both.
Monday, March 12, 2012
Nutrition ABCs: Vitamin D
Many moons ago, I thought it would be cool to start a little encyclopedia of nutrition terms I wanted you all to know more about. I made it to the letter C. Ahem...onward and upward! I think it is time to pick up this little theme once again. Nutrition is getting no less confusing...and we are still a wee bit unhealthy as a society. Just sayin'.
I started the Nutrition ABCs in 2010. A was for anti-oxidants; b was for broccoli and c was for calories...so now we are on to d. Which, of course, means we must chat about vitamin D!
The news on vitamin D seems to have cooled off as of late; just a few years ago you could hardly pick up a magazine or turn on the news without seeing a story on vitamin D. And rightly so: long dismissed as simply the ugly best friend of calcium in the quest for bone health, vitamin D finally got to stand out in the spotlight. What has changed since my last post on vitamin D? Well, the Institute of Medicine and Health Canada did indeed change their recommendations on vitamin D. What was the cutting edge of the research is becoming accepted nutritional fact: we need more vitamin D. Health Canada now recommends 600IU for those aged 7 - 70. The upper limit, or amount at which there is no foreseen risk of daily use, has been doubled to 4000IU. Again, most vitamin D experts would consider this conservative.
So what will vitamin D actually do for you? Research is growing in the areas of heart health, cancer prevention, prevention of type 2 diabetes and auto-immune diseases and even weight loss. However, some of the challenges with this research (especially in the initial stages) include ineffective dosing and lack of placebo-controlled, double blind trials. However, the evidence is considered substantial enough for many in the world of health and research to call for a widespread increase in intake.
While called a vitamin, vitamin D is actually more biologically similar to a steroid hormone once activated by the kidneys. It has an effect on almost every organ and tissue in the body and helps to modulate the immune system. This is one of the most interesting outcomes of vitamin D intake to me; considering all of the attention on chronic inflammation in the progressive health literature, keeping the immune system tuned is important. And most of us have not been getting enough vitamin D. Ideally, your physician would assess your blood levels of vitamin D so you can be dosed accordingly. In the absence of that knowledge, a safe bet for almost all adults would be 2000-3000 IU of vitamin D3 a day. As mentioned in my previous post, you can't really rely on most food sources (except for fatty fish like salmon) for an effective dose. As a dietitian, I don't like people to pop pills unnecessarily; however, I routinely recommend vitamin D to my clients.
PS. Read my opinion...and then discuss it with your health professional. This post is offered as information only; this article can't take the place of in person consultation with a qualified health professional. And no, I don't have a financial stake in any supplement company. I just want you to be healthier!
Sunday, August 15, 2010
Nutrition ABCs: Calories
There were a lot of ways to go with the letter C....like carrots, carbohydrates or calcium....but I thought that it might be a nice idea to really get back to basics and talk calories. Calories are top of the list on the nutrition facts panels, so they must be important right? We count calories when we are watching our weight, we burn calories through activity and food manufacturers market their 100 calorie snacks as being better for us than those with larger (and less round) numbers.
We talk calories every day...so what exactly is a calorie and why does the amount of calories we eat matter?
Here is the scientific version -
A calorie is a unit of heat energy: to be accurate, what we call a calorie in nutrition speak is actually a kilocalorie, or 1000 calories of heat energy. To simplify, we won't concern ourselves with that technicality but say that one calorie is the amount of energy in the form of heat it takes to raise the temperature of one gram of water by one degree Celsius. Huh?
What this definition illustrates most importantly is that a calorie is not just a made up concept (which is a question I have been asked before...so yes, Virginia, a calorie is a real thing!).
When a food has 250 calories, for example, it means that it can provide your body with 250 units of energy once it is digested and absorbed. To learn how many calories are in a food, the food is actually burned in a lab in a device called a bomb calorimeter to determine how much energy it gives off. A simpler way of doing this is to calculate the calories based on known values for the ingredients (but all data had to come from somewhere...burn baby burn!).
While food provides energy, our body spends it keeping us alive: from breathing to digesting, talking to walking, each function and activity we carry out requires energy and the food we eat provides it. Think of it like a living bank account: if our bills and expenditures keep draining the account and we put nothing in it, we are going to bounce our checks and soon our phone will be turned off and we will lose our homes.
Our best research based equations to determine how much energy we need in a given day are not really that accurate and can over or underestimate by 10 - 30%. The best way of measuring how much energy a person needs is to actually contain them within a hood and measure their respiration on something called a metabolic cart. By measuring the use of oxygen and release of carbon dioxide, we can measure the energy that a person requires to maintain life. However, most of us will not get the opportunity to try out this process; the best way to know if we are doing well is to determine whether our weight is stable. If it is, we are doing a good job of maintaining energy balance: the calories in roughly equal the calories going out.
If we were to eat nothing or deprive our bodies of adequate energy for long periods of time, we end up with an energy deficit and our bodies go into conservation mode. Doing so moderately is how we lose weight...long term or severe deprivation wreaks havoc on our optimal metabolic state and affects everything from our energy levels to our immune system to our strength and mental function. And our bodies are smart: let your calorie intake drop too drastically and your body will respond in kind by lowering its rate of metabolism, meaning that you will need fewer calories just to maintain your weight...which is how chronic dieting can get you into trouble and encourage weight gain long term.
Our body stores energy mainly in fat cells: one pound of fat tissue stores 3500 calories of energy. So to lose a pound, we have to create a deficit of about 3500 calories, which most health professionals would counsel you should do over about 4-7 days for a healthy, moderate loss of one to two pounds a week. To gain a pound, you need to consume about 3500 calories more than you need, which seems like it would be tough to do but it sure can sneak up. Here is a great example -
Say you go out to Starbucks and get a regular coffee Frappucino because it is a hot summer day. You don't go crazy and get whipped cream or a large size and so your treat sets you back about 140 calories. That seems pretty reasonable, doesn't it? But let's say that you drink that Frappucino in addition to your regular diet...you don't eat less during the day or exercise more to compensate. And say that you enjoyed that Frappucino so much that you decide to get one the next day and the day after that and continue to do so for one year. Over that year, you would have eaten 51,100 extra calories. And if your body is efficient and turned each 3500 calories into a pound of fat, you would have the potential to have gained 14.6 pounds. All by having a Frappucino a day. The upside to this equation is that the reverse is true: take that drink out of your daily routine and you can lose weight without making any major changes to your diet.
So where does the energy (or calories) in a food come from? From the macronutrients they contain: carbohydrates, fats, protein and alcohol. Water, vitamins and minerals while essential for life do not provide energy (so they don't contain calories). Fat contains 9 calories per gram and is the richest source of energy. Carbohydrates and protein both provide 4 calories per gram and alcohol rings in at about 7 calories per gram. When people say that fat is fattening, it is not because it has any special evil powers but it is easy to get more energy than you need when it is more than double the energy, gram for gram, over carbohydrate or protein foods.
It can be easy to make the mistake that all that matters when it comes to health or weight is calories - and many health professionals fall into this trap too. Note the low fat fiasco of the 1990's in which we switched to tons of processed fat free carbohydrate snacks and got fatter than ever. While calories provide energy and ensuring a good energy balance is important for a healthy weight, calories tell you nothing about the nutritional value of a food: the nutrients it provides, the way it affects your blood sugar or how satisfying or filling it is.
So why do calories matter? My number one rule of healthy eating is to generally eat whole foods without fancy packages...fruits, vegetables, whole unprocessed grains, lean proteins and dairy (or non-dairy). If you follow this rule, it is unlikely you will need to count calories to maintain a healthy weight (and note that many of these foods don't even have nutrition facts panels!). However, if you are looking at processed foods like cereals, snacks or most importantly, fast food and restaurant foods - you can use the calories to compare a better choice.
Hmm...this post could easily go on and on so I might stop there....but first I'll give you the Coles Notes version:
- A calorie is a scientific unit of heat energy used to measure the energy that foods give you or that human activities consume.
- The calories in food come from fat, protein, carbohydrates or alcohol...not from water, vitamins or minerals.
- Calories are important because if we consume more energy than we spend, we will end up gaining weight.
- Calories will not, however, tell you anything about the nutritional quality of the food which has a bigger impact on your overall health (provided you are not gaining weight).
if you have any other questions, let me know and I will address them in an update!
In good health,
Desiree
We talk calories every day...so what exactly is a calorie and why does the amount of calories we eat matter?
Here is the scientific version -
A calorie is a unit of heat energy: to be accurate, what we call a calorie in nutrition speak is actually a kilocalorie, or 1000 calories of heat energy. To simplify, we won't concern ourselves with that technicality but say that one calorie is the amount of energy in the form of heat it takes to raise the temperature of one gram of water by one degree Celsius. Huh?
What this definition illustrates most importantly is that a calorie is not just a made up concept (which is a question I have been asked before...so yes, Virginia, a calorie is a real thing!).
When a food has 250 calories, for example, it means that it can provide your body with 250 units of energy once it is digested and absorbed. To learn how many calories are in a food, the food is actually burned in a lab in a device called a bomb calorimeter to determine how much energy it gives off. A simpler way of doing this is to calculate the calories based on known values for the ingredients (but all data had to come from somewhere...burn baby burn!).
While food provides energy, our body spends it keeping us alive: from breathing to digesting, talking to walking, each function and activity we carry out requires energy and the food we eat provides it. Think of it like a living bank account: if our bills and expenditures keep draining the account and we put nothing in it, we are going to bounce our checks and soon our phone will be turned off and we will lose our homes.
Our best research based equations to determine how much energy we need in a given day are not really that accurate and can over or underestimate by 10 - 30%. The best way of measuring how much energy a person needs is to actually contain them within a hood and measure their respiration on something called a metabolic cart. By measuring the use of oxygen and release of carbon dioxide, we can measure the energy that a person requires to maintain life. However, most of us will not get the opportunity to try out this process; the best way to know if we are doing well is to determine whether our weight is stable. If it is, we are doing a good job of maintaining energy balance: the calories in roughly equal the calories going out.
If we were to eat nothing or deprive our bodies of adequate energy for long periods of time, we end up with an energy deficit and our bodies go into conservation mode. Doing so moderately is how we lose weight...long term or severe deprivation wreaks havoc on our optimal metabolic state and affects everything from our energy levels to our immune system to our strength and mental function. And our bodies are smart: let your calorie intake drop too drastically and your body will respond in kind by lowering its rate of metabolism, meaning that you will need fewer calories just to maintain your weight...which is how chronic dieting can get you into trouble and encourage weight gain long term.
Our body stores energy mainly in fat cells: one pound of fat tissue stores 3500 calories of energy. So to lose a pound, we have to create a deficit of about 3500 calories, which most health professionals would counsel you should do over about 4-7 days for a healthy, moderate loss of one to two pounds a week. To gain a pound, you need to consume about 3500 calories more than you need, which seems like it would be tough to do but it sure can sneak up. Here is a great example -
Say you go out to Starbucks and get a regular coffee Frappucino because it is a hot summer day. You don't go crazy and get whipped cream or a large size and so your treat sets you back about 140 calories. That seems pretty reasonable, doesn't it? But let's say that you drink that Frappucino in addition to your regular diet...you don't eat less during the day or exercise more to compensate. And say that you enjoyed that Frappucino so much that you decide to get one the next day and the day after that and continue to do so for one year. Over that year, you would have eaten 51,100 extra calories. And if your body is efficient and turned each 3500 calories into a pound of fat, you would have the potential to have gained 14.6 pounds. All by having a Frappucino a day. The upside to this equation is that the reverse is true: take that drink out of your daily routine and you can lose weight without making any major changes to your diet.
So where does the energy (or calories) in a food come from? From the macronutrients they contain: carbohydrates, fats, protein and alcohol. Water, vitamins and minerals while essential for life do not provide energy (so they don't contain calories). Fat contains 9 calories per gram and is the richest source of energy. Carbohydrates and protein both provide 4 calories per gram and alcohol rings in at about 7 calories per gram. When people say that fat is fattening, it is not because it has any special evil powers but it is easy to get more energy than you need when it is more than double the energy, gram for gram, over carbohydrate or protein foods.
It can be easy to make the mistake that all that matters when it comes to health or weight is calories - and many health professionals fall into this trap too. Note the low fat fiasco of the 1990's in which we switched to tons of processed fat free carbohydrate snacks and got fatter than ever. While calories provide energy and ensuring a good energy balance is important for a healthy weight, calories tell you nothing about the nutritional value of a food: the nutrients it provides, the way it affects your blood sugar or how satisfying or filling it is.
So why do calories matter? My number one rule of healthy eating is to generally eat whole foods without fancy packages...fruits, vegetables, whole unprocessed grains, lean proteins and dairy (or non-dairy). If you follow this rule, it is unlikely you will need to count calories to maintain a healthy weight (and note that many of these foods don't even have nutrition facts panels!). However, if you are looking at processed foods like cereals, snacks or most importantly, fast food and restaurant foods - you can use the calories to compare a better choice.
Hmm...this post could easily go on and on so I might stop there....but first I'll give you the Coles Notes version:
- A calorie is a scientific unit of heat energy used to measure the energy that foods give you or that human activities consume.
- The calories in food come from fat, protein, carbohydrates or alcohol...not from water, vitamins or minerals.
- Calories are important because if we consume more energy than we spend, we will end up gaining weight.
- Calories will not, however, tell you anything about the nutritional quality of the food which has a bigger impact on your overall health (provided you are not gaining weight).
if you have any other questions, let me know and I will address them in an update!
In good health,
Desiree
Thursday, June 3, 2010
Nutrition ABCs: Broccoli
Image from the mysterious pro-broccoli website...http://www.themiraclefood.ca/
Once so beloved as a superfood, now it seems like we have all but abandoned broccoli for brooding winter greens and exotic tropical berries. Dating back to the Roman Empire, broccoli belongs to the family Cruciferae, which refers to its Cross like shape.
Broccoli deserves to be back on your nutrition radar: loved by kids and adults alike (sorry Elmo!), broccoli lends itself to a diverse range of cuisines, preparation techniques and is one of the best research vegetables in terms of chronic disease prevention.
Rich in anti-oxidants for healthy aging and loaded with vitamins and minerals for optimal health, broccoli is one of those foods that should find its way into your diet at least a few times a week. Need more inspiration to rekindle the love for this emerald crucifer? Read on...
Sulphoraphane A sulphur containing compound that helps activate Phase 2 enzymes in the liver responsible for detoxification and elimination, a new study in the journal Clinical Cancer Research (May 1, 2010 16(9): 2580-90) confirms that high doses of sulphoraphane are able to eliminate breast cancer stem cells (CSCs) and stop tumour production. Sulphoraphane may also inhibit H.Pylori infection, a leading cause of stomach ulcers.
Indole-3-Carbinol I3C is another anti-cancer powerhouse: I3C has been also been shown in clinical research to suppress breast cancer development, especially in estrogen sensitive tumour types. (Most recent publication? Click Here) I3C may also have a role to play in suppressing the growth of prostate cancer.
Folate An important nutrient for women who may become pregnant, folate reduces the risk of spinal cord defects in the fetus. Folate is also essential for healthy cell cycle regulation and DNA repair. 1 cup of broccoli contains 94 mcg of folate.
Calcium On a gram by gram basis, broccoli is richer in calcium than milk! Not just for healthy bones, calcium is critical for muscle contraction, healthy nerve transmission and even blood pressure regulation. The vitamin C in broccoli also helps to aid in calcium absorption.
Vitamin C Richer in vitamin C than oranges, 1 cup of broccoli contains 123 mg of vitamin C. Vitamin C helps build collagen for healthy skin, supports immune health and wound healing and aids in absorption of vegetarian iron sources (non-heme iron).
Magnesium Looking for more magnesium? Broccoli packs a punch here too! One cup contains 39 mg of this calming nutrient; magnesium is also important for a healthy heart, blood sugar regulation and muscle contraction.
Lutein and Zeaxanthin These anti-oxidant phytochemicals are critical for eye health and may help prevent age related macular degeneration and cataracts, leading causes of blindness in later years.
Want to get healthier? Eat broccoli! Try to eat 1 cup of broccoli 3 times a week; enjoy it raw, steamed, stirfried or roasted! Avoid overcooking as the sulphur compounds will be degraded and you can tell by the telltale sulphurous odour. Look for vibrant green stems that are firm and eat promptly - many nutrients, such as vitamin C, degrade quickly when stored. Local broccoli not in season? Frozen broccoli is a great option as it is picked at the peak of freshness...lightly cook directly from the frozen state for best results.
If there are any requests for a "C" post...let me know! Some interesting options: Carotenoids, Co-Enzyme Q10, Calorie, Carbohydrate and more....
Eat up...it's summer!
Desiree
Tuesday, May 18, 2010
Nutrition ABCs: Anti-Oxidants
Photo taken from the BC Blueberry Council Website http://www.bcblueberries.com/
I picked up Leslie Beck's revised The Complete A-Z Nutrition Encyclopedia: A Guide to Natural Health last week and have been devouring it since...then I got inspired to finally do a blog post. It has been such a busy year that my goal of one post a week has quickly gotten away from me. But change is on the horizon so I am looking forward to putting a lot more content on here for you all to enjoy!
I thought it would be fun to do my own little encyclopedia on topics that I find I get frequent questions about - so let's start at the beginning!
A is for anti-oxidants...
Anti-oxidants are still a hot topic after all of these years and yet, many of us still don't fully understand them. So what is an anti-oxidant?
Anti-oxidants are substances that are either naturally occurring in our bodies or occur in nature which help to combat oxidative damage to our tissues. Oxidative stress from normal body metabolism, stress, lifestyle choices, intense exercise and more creates free radicals which have the potential to wreak havoc on our cells. Free radicals are unstable molecules that cause damage to our body's proteins, cells and DNA as they attempt to stabilize themselves.
Fortunately, we come equipped with a built in anti-oxidant defense system to mitigate the fallout; however, our internal defenses can be overwhelmed when the oxidative stress is too great. When damage accumulates over time we see the results in chronic disease and the signs and symptoms of aging. This is where dietary anti-oxidants come into play.
Anti-oxidants in food come in many forms...here are a few examples:
- phytochemicals like anthocyanins in blueberries and pomegranate
- vitamins like A, C & E
- minerals like selenium
- enzymes like superoxide dismutase
So how do we evaluate which anti-oxidants are best for us or which foods are the best source of anti-oxidants?
This is a challenge as our knowledge of how anti-oxidants work in the body is still fairly new. Does an anti-oxidant work on its own or does it work best in tandem with another? In the case of vitamins C and E, one "recharges" the other and so they work best together. Is more of an anti-oxidant better? In the case of many, including vitamin C, too much vitamin C can actually act as a pro-oxidant and therefore cause damage instead of preventing it. If we isolate an anti-oxidant from food, does it work the same as when we consume it in food? Maybe...as you can see, nutritional science is still playing catch up with the gifts that nature has provided us.
One method of evaluating the levels of anti-oxidants in foods is their Oxygen Radical Absorbing Capacity, or ORAC. Foods can be measured in terms of their ORAC value per 100 grams of food. Useful in some ways, ORAC values can tell us that spinach is a healthier choice than iceberg lettuce as it has a higher ORAC value or that the lowly prune carries just as much of an anti-oxidant punch as blueberries. But ORAC levels don't tell us how that capacity will translate into supporting our body's anti-oxidant defense system or what kind of anti-oxidants a food contains.
Should you take anti-oxidant supplements?
It depends...in the case of vitamin E, we have learned that supplementing does not appear to have the health benefits we once expected and for certain populations, like smokers, it can actually do more harm than good. However, vitamin E rich foods such as whole grains and raw seeds carry numerous health benefits. Beta carotene supplements may also not be the nutritional star we were hoping. Other anti-oxidants, like Coenzyme Q10 and EGCG from green tea, are well studied and can be beneficial for some.
So what is my best source of anti-oxidants?
Beautiful, natural food! A plant based diet that maximizes fresh fruits and vegetables, intact whole grains, legumes and raw nuts and seeds will provide you with a wide variety of anti-oxidant nutrients for better health. These nutrients will be complexed in synergistic combinations, the way mother nature intended and provide numerous other nutrients such as fibre.
Any foods I should try to eat more of due to their anti-oxidant benefits?
Here is a just a handful of the many plant world superstars...green tea, blueberries, pomegranates, dark leafy greens like kale and spinach, raw nuts and seeds like walnuts, Brazil nuts and pumpkin seeds, citrus fruits, tomatoes, turmeric and fresh green herbs like thyme and basil.
To your health,
Desiree
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