Most people who count calories for weight loss or weight management assume it’s an exact science. It’s not. Here we outline 5 reasons calorie counting (i.e. logging your food to calculate intake) is fundamentally flawed.
Make no mistake, the principles of energy balance work: Take in more calories / energy than you expend, you gain weight. Take in fewer calories / energy than you expend, you lose weight. However, counting calories as a way to try to know, and control, your energy intake is fundamentally — sometimes hopelessly — flawed.
For starters, you can’t really trust that the calorie (and macronutrient) numbers you see on food packages are accurate. You see, the way they’re calculated — if they’re calculated at all — is surprisingly imprecise. Plus, even if food package numbers were precise, once the food is cooked, or chopped, or blended, the amount of energy available for digestion and absorption changes.
Then there’s what happens once that food enters your body… In the end, even something that seems as simple as knowing how many calories you’re taking in (and absorbing) can be influenced by dozens of unexpected factors.
Top 5 Reasons why calorie counting does not always work:
- Food companies may use any of 5 different methods to estimate calories, so the FDA permits inaccuracies of up to 20%. So “150 calories” actually means 130-180 calories.
- We don’t absorb all of the calories that we consume. Some calories pass through us undigested, and this varies from food to food.
- How you prepare food changes its local calorie count. Cooking your food generally makes more of the calories available for absorption, and food labels don’t always reflect that.
- Individuals absorb calories uniquely and variably. Our own individual gut bacteria can increase or decrease the calories we absorb. People with a higher proportion of Firmicutes bacteria absorb an average of 150 calories more per day than those with a higher proportion of Bacteroidetes.
- People aren’t great at eyeballing portion sizes. Studies show that people mis-measure portions about two thirds of the time, so it’s easy to accidentally consume a lot more calories than you intend to.
What’s the solution?
Commit to a daily movement practice and ballpark food portions using a hand measurement system. In addition to that stick to whole foods, and fresh fruits and vegetables.