Calorie Counting: Yay or Nay?
CN: Diet and weight loss
The best way to lose weight is to eat less calories and burn more calories, so counting calories just makes sense, right? So many people have used calorie counting, it must work. The government is demanding calorie labels on everything, so it’s probably something we should all take into account right?
Well, maybe not. Many people assume that calories are simple, but in reality a lot more goes into the impact of calories on your body than the number on the box, and as a health measure calories cannot tell you whether your diet is good or not. One of the biggest downsides to calorie counts is that they don’t give you any information about the nutrition that you’re getting. 200 calories of gummy bears is not the same as 200 calories of spinach because one actually provides you with vitamins, protein, and iron, while the other is empty. This affects your energy and hunger moving forward, and can also affect deficiencies like anemia. The common wisdom is that a calorie is a calorie, but that isn’t true when it comes to how your body reacts to the calorie and whether the food is nourishing you.
So at the very least calories alone are not an accurate way to gauge the healthiness of a diet. But in addition, calories themselves are more complex than they seem at first glance when it comes to using them as a way to lose weight. Oftentimes, the calories that we see on a package are not the actual number of calories that are absorbed by our body when we eat the food. Different foods digest differently (duh). Some of them are more easily broken down, which means we get more calories from them. In contrast, something like a nut is difficult to digest and often passes through the body partially undigested thanks to its strong cell walls. That means we don’t end up actually absorbing many of the calories contained in that nut.
Another element is whether something is cooked or not. Cooking can again break down cell walls and make it easier for us to digest more calories, but an addition element of cooking is that it makes food softer and easier to chew. This means less calories spent actually eating the food. The actual process of how difficult it is to chew and swallow a food can make a difference in the end calorie value of a food. As an example, celery is a negative calorie food because it takes more calories to chew it than it provides you in the end. When you’re thinking about how many calories you might get out of a food, you should remember that food doesn’t happen in a vacuum: the preparation and eating do burn calories as well.
Additionally, different bodies digest and absorb calories differently. This is affected by both gut bacteria and genetics, and is extremely individual. In a study of inbred rats (meaning very genetically similar) that were fed the exact same diet, some gained weight and others lost. Obviously we can’t map this one to one onto human beings, but it is good evidence that individual bodies need individual attention (and if you’ve ever tried to diet with a friend, you’ve probably come to the same conclusion). There is also some evidence that people who are obese will absorb more calories from the same food as those who are smaller, and that it is nearly impossible for them to lose weight beyond a certain point (just as it is difficult to gain weight if you’re naturally skinny).
So it seems clear that figuring out exactly how many calories we would get from a food is extremely difficult because it varies based on type of food, preparation, and the person eating it. But even if we do find accurate calorie information, does it help with weight loss? On a large-scale level, the answer appears to be no. Nearly every study of restaurants that added calorie counts to their menu saw no change in average calories per customer, or a slight increase. In general, those who did lower calories (and it was again slight) were in high-income, high-education areas that already had low levels of obesity (and are considered low risk). So on a society wide level, paying attention to calories does not inspire much change in behavior, at least in the ways that it has been implemented thus far.
What about the individual level? Well there is obviously evidence that depriving yourself of calories will lead to weight loss eventually.But is this the best and healthiest way to lose weight? Will it help with long term weight loss and keeping weight off in the long run? On these counts, the jury is still out, but there is a lot of evidence that says exclusively focusing on calories is not a healthy way to lose weight. First, keeping weight off appears to be easiest when one follows a consistent diet, exercises, and pays close attention to the types of food that one is eating. Calories are not mentioned in this study at all. Second, heavy calorie restriction can often lead to binging in response, as well as a slowing of the metabolism (particularly if breakfast is restricted or skipped). Third, studies of weight loss often point towards type of food as being at least as important as calories. Different types of food will make you feel more or less full, which will also help you lower calories. There are many other tactics (such as portion control, consistency, and exercise) that make more sense than calorie restriction.
A final note about the efficacy of calorie restriction: severe calorie restriction is dangerous. The Minnesota Starvation Experiment showed that even semi-starvation (a diet of about 1500 calories per day) can have serious and lasting side effects including depression, self-mutilation, preoccupation with food, decrease in metabolism (with impacts on heart, body temperature, and respiration), and isolation. Many popular diets today recommend going as low as 800 calories per day (1200 per day is considered starvation). If calorie restriction is your chosen weight loss program, you need to be incredibly careful as it is easy to do damage to your body and your mind.