The “calories in, calories out” hypothesis has been disproven- Why it will always be harder for some people to lose weight
Consider the following scenario:
Person A- Exercises 30 minutes a day, eats 3 small meals every day, totaling 3000 calories.
Person B- Exercises 30 minutes a day, eats the same amount.
Person A is gaining an average of 5 pounds per month, and person B isn’t gaining any weight at all.
According to the old “calories in, calories out” hypothesis that’s still taught in most medical schools, those two people should have around the same rate of weight gain, even if they started out with different weights due to size, muscle mass, bone density, etc.
Clearly, there must be another explanation for this, and it turns out there is. People who are overweight or obese are much more likely to have a microbiome that is more efficient at extracting calories from their food. What does this mean? It means certain strains of bacteria that reside in our intestines are more metabolically active, and better at using their enzymes to break down the complex carbs we eat into simple sugars.
The body then converts this glucose into fat once it’s released into the bloodstream, and that fat is deposited into our fat cells throughout the body. Obese people are more likely to be born with these more active strains of bacteria because their moms had them as well, and passed them on to their babies. But they can also be acquired from diet and exposure to animals. In fact, there are a few viruses that animals can infect us with that are known to cause obesity as well, as the author of “The Secret Life of Fat” explained.
So, two people could have the exact same caloric intake per day, exercise the same amount, and one could still end up weighing significantly more than the other, due to the different strains of bacteria that are residing in their intestines.
One of the misconceptions out there is that obese people always eat more than the rest of us. Though that may be true in many cases, it isn’t necessarily true in all cases, or even a majority of them. They could be eating the same amount, as I’ve explained above. Therefore, if they wanna lose weight, they have to eat less than the rest of us.
This explanation of the cause of obesity doesn’t even take into account genetic and biochemical differences between people, nor does it take into account epigenetics and environmental factors, which add another layer to the complexity of this disease. For example, some people have genes which are involved in the leptin signaling system, which cause them to crave sugar and fat more, and thus eat more than the average person. These people also tend to have genes that cause them to convert carbs to fat more efficiently.
It remains true that we’re responsible for our decisions, and willpower and attitude are the primary drivers behind obesity. But we also have to keep in mind that many people struggling with eating disorders and their weight have significant disadvantages that they’re often not aware of. It’s important for doctors, and the rest of us, to make the aware of these things, because knowledge is power.
Once they realize their struggles with their weight and cravings aren’t all their fault, that there’s a reason why it’s harder for them to lose weight than others, and that they can control their weight, it can change their mindset and give them hope. This in turn can give them the motivation they need to change their diet and lifestyle, and to form new habits that they’ll keep for the rest of their lives. They no longer have to hopelessly bounce around from one yo-yo diet to another, with no results to show for their efforts. Let’s give people this knowledge, so that hopefully they can use it to change their lives, and pass it on to others who can do likewise.