Over the course this program I have consumed a ton of food. Seriously. I was texting with my friend I realized I buy 9 pounds of meat a week in addition to 3 dozen eggs + various veggies. That’s a lot for a girl my size (5’5”, 130 lbs). Sure, I work out but I easily consume upwards of 1800+ calories a day. And, thanks to MyFitnessPal, I’ve learned that the majority of my calories come from fat.

So why I haven’t I gained weight? Well besides writing that fat isn’t the enemy here there is another piece of the puzzle. As usual, it’s complex and science-y but I’m going to try my best to write it in plain English.

Popular wisdom says that in order to maintain a healthy weight we need create equilibrium between the calories we expend and the calories we consume. “The same amount of energy IN (calories consumed) and ENERGY OUT (calories burned) over time = weight stays the same,” writes the NIH. How come then, even though millions of Americans restrict calories and work out, we have an obesity epidemic?

Because Americans are eating an overabundance of sugar and refined flour as part of their every day diets.  Fructose (found in high-fructose corn syrup) is metabolized by our liver and elevates our insulin levels. Consistently high insulin results in our bodies becoming insulin resistant and then we pack on the weight (I broke down our body’s reaction to insulin in more detail in this post).

Many people invoke thermodynamics when it comes to weight loss. The problem here is that our bodies are not closed systems. A lot more can happen to calories besides being burned or stored (Ragen over at Dances with Fat does a great job explaining what our body does with these nutrients) and our bodies don’t just start  and continue losing weight once we cut calories because our body thinks we’re starving. Once again, Ragen explains it in better detail here.

In summation: Your body is going to metabolize 100 calories of chicken a lot differently than 100 calories of Twinkies. The quality of food you eat is just as important as the quantity you eat.

Sources/Recommended Reading:

Is a Calorie Really a Calorie? Metabolic Advantages of Low-Carbohydrate Diets

“A calorie is a calorie” violates the second law of thermodynamics

Why the Campaign to Stop America’s Obesity Crisis Keeps Failing