How is it that you can take a group of 10 women, feed them the exact amount of calories, make them sweat for exactly the same amount of cardio, and you’ll get 10 different outcomes in how their body responds? Ever since we were introduced to the idea of calories in calories out it seemed like a person’s weight could be broken down to a simple thermodynamic principle. If it takes exactly 3,500 calories to burn 1 pound of fat, then simply reducing 3,500 from your weekly eating would result in a scientifically promised outcome of 1 pound of weight loss per week. Easy peasy right?
Except there’s a flaw with this theory. While calorie expenditure can be accurately measured using a calorimeter, the human body is not a simple closed container. We can easily measure the amount of calories going in, but we really can’t measure the amount of calories going out. There’s a whole bunch of factors that determine how our bodies actually use that calorie that we ingested including our BMR (basal metabolic rate) and how our hormones, specifically insulin and cortisol react to the calorie. A calorimeter doesn’t have a thyroid.
I knew that some people had a harder time at losing and keeping weight off than others and whenever I overheard someone being snarky and saying that certain people were just lazy and lacked self-control inside I bristled. My grandmother wasn’t lazy, yet she was always a large woman. I ate the same amount of food as my little sister, yet she had to sweat it out in the gym to stay slim, while I hated exercise. So what made some people naturally thin and others naturally larger?
I just came across Dr. Jason Fung’s book The Obesity Code and it’s totally changed how I view eating. He says that insulin, not calories, is the main determining factor in how our bodies store fat. For instance, if you take 3 people, a Type 1 diabetic, a Type 2 diabetic, and a person without diabetes and feed them all the same amount of calories, you will get 3 very different outcomes. The type 1 diabetic doesn’t have any insulin to help process the sugar in his food and without an insulin shot will eventually pee out the sugar, waste away, and die. A person with Type 2 diabetes has too much insulin so the sugar that he ingests will mainly be stored as fat because that’s what insulin does. The person without diabetes will burn some fat and store some fat based on his BMR. I know this is way oversimplified, but it’s just to prove a point that we’ve been focusing on calories, when we should be focusing on insulin. More specifically, the kinds of calories that affect our insulin which in this case is sugar. So here’s the next question, if lowing insulin is our goal, how do we do that?