The next time some doorknob tries to “prove” that diet and exercise makes all fat people thin by citing “calories in/calories out” or “the laws of thermodynamics,” send them this link. The fact that we can’t even accurately predict the gas mileage of cars (aka, actual fucking machines) should be a pretty good fucking clue that “3,500 calories = 1 pound” is a sketchy proposition.
The post is long and technical, but when researchers from the NIH and WHO analyzed the calories in/calories out equation, it looked more like this:for every 10 calories per day you restrict, you will lose 1 pound, with half of that weight dropping after a year and 95% dropping by three years. So, if you cut 500 calories per day (or 3,500 per week), that’s 25 pounds after one year and 48 pounds after three years. Compare that the the “laws of thermodynamics” which say a 3,500 calorie restriction will cause 1 pound of loss per week, or 52 pounds after a year and 156 pounds after three years.
As the research team says:
This ubiquitous weight-loss rule (also known as the 3500 kcal per pound rule) was derived by estimation of the energy content of weight lost but it ignores dynamic physiological adaptations to altered body weight that lead to changes of both the resting metabolic rate as well as the energy cost of physical activity.
The “laws of thermodynamics” people then claim you just have to drop your caloric intake progressively to keep up with your metabolism, which drops as you lose weight. Except there isn’t a single study out there that proves such a dynamic strategy actually produces better short- or long-term results in weight loss. Instead, they will point to Before and After photos and thermodynamics and common sense and and and…
Anyone who turns health a math problem is clueless and confused, and the only thing they have to hang their hat on is a fuzzy recollection of the laws of thermodynamics from high school. You don’t have to cut calories to improve your health; you do need to improve the quality of your diet and get some exercise though. Of course, when fat people say they DO eat a healthy diet and exercise, they’re told they are lying because of the “laws of thermodynamics.”
You won’t win when you argue with low-information weight loss evangelists, but you can get educated yourself so that you can see the glaring holes in their logic when they confront you.