Do calories count? Part 1
Many people think weight loss is simply a matter of eating less calories in the form of food/drinks and burning more calories in the form of exercise.
“A pound of fat is equal to about 3500 calories, so if you eat 500 calories less than you burn each day, in seven days you’ll lose a pound of fat.”
How many times have you heard this? Ah…if only things were that simple. But they’re not. This calorie myth relies on a drastic oversimplification of how calories are used in the body. And unfortunately, thinking about weight loss in this way has left many people frustrated and at a loss to know what to do when this method hasn't worked for them.
If you have ever tried or are currently trying to lose weight, ask yourself these questions…
Do you want to lose weight just for summer or for good?
Do you want to improve your health markers too?
Do you want to improve your metabolism or harm it?
Do you want to lose any weight or fat weight?
Do you want to strengthen your immune system or weaken it?
I think I know what your answers would be but most people’s approach to weight loss is through a calories in calories out approach. It makes sense on the surface and simple is nice but our bodies don’t operate like a simple machine and are way more complex than just solving basic arithmetic.
For one thing calories in and calories out are not independent variables.
If they were you could drop energy intake and maintain your resting metabolic rate while burning the same amount of energy digesting food (even though you’re eating less of it) and increase the amount of time spent on working out to burn more calories. The fat would melt off at a predictable, constant rate. You probably know from experience that this is not the case.
So, what’s going on?
In reality, the amount and type of calories we eat affect the amount of energy we burn.
During calorie restriction, the body “defends” its body weight by lowering resting metabolic rate and reducing the desire to keep physically active.
I don’t deny the importance of calories. Calories absolutely count. But it's not as simple as counting what goes in and what comes out - that in itself is an impossible task for many reasons.
And then there’s the hormonal responses to what goes on when we eat and exercise in certain ways…more about that in Part 2 of this blog.
Why You Can’t Count on Calorie-Counting for Weight Loss
1. We can’t accurately measure our food.
Most packaged foods in supermarkets have nutritional labels attached. Even some restaurants are beginning to include this data on their menus with calorie counts for each item. The problem is, we implicitly trust that this information is accurate. Except this is not the case. Food manufacturers have been known to underreport calories by 20% and still be allowed to publish these statistics.
Even if they were accurate representations of the calories we were eating, people are also consistently underestimating what they consume. Snacks and mouthfuls here and there get forgotten and if the food comes from someone else's plate then it doesn’t count right? Calorie free food!
This is further complicated when we eat out at restaurants. We can’t see the added extras that go into the foods we are served, and the portion sizes are the same regardless of whether we are male or female, large or small. Unless you weigh and measure everything you eat, it’s virtually impossible to get an accurate measurement of food intake. That’s not to say there isn’t any value in maintaining a food diary. Sometimes, just writing things down helps us rethink what we’re about to put in our mouths.
Even it it were possible to calculate the exact number of calories in the food we eat, which we have already established it is not, it would still be a very ineffective way to lose body fat. Why? Because by focusing all our attention on only calories we are not taking into account all the other stuff in our food such as the macronutrients our meals are made up of and the many toxic chemicals which unfortunately are present in most processed foods that are produced and sold. The reasons why many people are gaining weight is actually because of the hormonal disruption these toxins create.
2. All calories are not the same.
Eating the same amount of calories from protein as carbohydrates or fats results in dramatically different hormonal responses by the body.
When protein is eaten, it stimulates the production of hormones that help reduce appetite, regulate blood sugar levels and helps you hold onto muscle when you’re on a calorie-restricted diet. (More of why that’s so important in Part 2)
Certain carbohydrates, on the other hand, stimulate the production of a hormone that shuts down the body’s ability to burn fat and can actually increase fat storage. It is a vital hormone in our body but also has the ability to cause lots of damage.
Fats do not cause a rise in this hormone and some fats may even cause a slight increase in metabolic rate.
The truth is, our bodies are not calculators and its functions are controlled by hormones which respond differently to different foods. Therefore, the varying hormonal responses the body reacts to has a direct influence on your metabolism and your ability to increase muscle or gain or decrease body fat and it is one of the main reasons why a calorie counting approach is futile.
3. The body doesn’t lose only fat when it loses weight.
When we use the “3500 calorie” rule for fat loss, it overlooks the fact that people don’t just lose fat. They also lose water and muscle. Muscle burns about three times more calories than fat. By losing fat and maintaining, or even increasing muscle, the reduction in metabolic rate can be minimised. (In Part 2 I will be explaining how to achieve this with regards to diet, exercise and lifestyle)
4. Metabolic rate drops when calorie intake drops.
When people lose weight, their metabolic rate drops due to the fact that they have less body tissue.
Therefore, when people eat fewer calories to lose weight, they usually see a plateau in weight loss as a result of this decrease. They then need to eat even less calories to continue to create a deficit between what is going in compared to what is going out. Then their body’s metabolism adjusts and weight loss slows again. Over time this can cause metabolic damage that can be difficult to repair and results in the common yo-yo dieting effect where you actually end up heavier than when you started and with a slower metabolic rate.
5. Another effect is a difference in the thermic effect of food.
The body burns a certain amount of calories just to break down and absorb the food we eat, so if we eat less food then less calories are burnt to break that food down, again narrowing the gap between calories in and calories out. Also, different macronutrients require different amounts of energy to break them down. To break down 100 calories of protein requires about 20-35 calories. Lets compare that to 100 calories of Carbohydrates which takes about 5-15 calories and 100 calories of Fat which takes only about 2-5 calories.
6. We can’t accurately measure our daily calorie expenditure.
Technology has come a long way in recent years. Activity and Heart Rate monitors help track our activity and estimate our calorie expenditure, but they’re far from perfect. They cannot precisely measure our calorie expenditure 24 hours per day. (To do that you would have to spend all day in a metabolic lab hooked up to all sorts of fancy equipment.) I know for a fact that if I ate the same number of calories my tracker told me I had burnt each day, I would definitely have gained weight. So, just like estimating the calories going in, estimating calorie expenditure is also going to have a pretty large margin of error.
7. As you get in better shape, you burn less calories at the same relative intensity.
Remember how those two flights of stairs used to leave you out of breath? After a while, they’re not such a big deal. Doing one pushup might have once felt impossible and now you can easily do twenty. Losing weight can be a factor in making these and other activities and exercises easier, but the body also becomes more efficient with movement over time. Muscles become better coordinated and energy is generated more efficiently. As a result, the body burns fewer calories to carry out the same activity. The “calories out” part of the calorie balance equation may drop as you become fitter that’s why it is vital you are following a well-designed training program where the intensity will increase each week.
8. Sorry to break this to you but exercising to ‘burn’ calories is not very effective.
People have the mistaken idea that exercise is a great way to create a large calorie deficit. But exercising doesn't burn a lot of calories and if you work out how many you would have burnt during the same amount of time just sitting still, it’s quite demotivating. To add to this, there is also evidence to show that the more you take part in formal types of exercise such as going to the gym, a yoga class or doing exercises at home, the less likely you are to be more active throughout the day so you could actually be burning less calories as a result of you efforts. Not a great scenario, I’m sure you will agree.
If calories burnt were the most important factor, then the best way to lose weight would be to hammer it out with as much endurance exercise as you can because that’s the most calorie intensive. Hey, guess what? That’s what a lot of people do and although they see no results, continue, but this type of activity often uses muscle tissue as it’s fuel so has a detrimental effect on your body composition as with less muscle your resting metabolism slows down meaning you have to eat even less to even remain the same weight! Also, as mentioned before, the more efficient you become at an activity, the less calories your body uses - same goes for endurance activities. The body is clever (annoying) like that.
I won’t even get into the fact that you may even ‘reward’ yourself with extra food as a treat for working out or that the type of activity you choose could be one that stimulates hunger and cravings. In addition, if that food is a carbohydrate that stimulates the production of the fat storing hormone, then you are creating a hamster wheel situation where you are going to get nowhere. You may well get ‘fitter’ but won’t lose any body fat.
I’m not suggesting that exercise is a waste of time, far from it. It has some amazing effects on our physiology that can assist with the fat loss process. But you must choose the right type of exercise to stimulate the correct hormonal response and not just choose it based on the number of calories it burns. (More about that in Part 2)
So now what?
If we can’t rely on creating a deficit by tracking the calories that go in against those that go out, and if there are so many other factors that are involved in losing unwanted body fat, what can we do?
Make sure you don’t miss Part 2 of this blog where I will be looking at a scientific approach to fat loss and will be giving some practical tips on how to sustain it for good.
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