Fat Loss Debunked: Why Crash Diets Can Make You Fatter

Raise your hand if you’ve ever asked yourself one of the following: “I’m exercising, lifting weights, and eating healthy, but why aren’t I losing weight?” “How come I look better, but my weight has gone up?” “Why do my jeans fit looser, but the scale says I’m heavier?” Alternatively, count yourself if you have ever lost 10-20lbs on a rapid fat loss diet, only to immediately put weight back on. Or if you looked flabbier afterwards! In this article, I’ll explain the how and why of this frustrating situation. I’ll also explain how to get the best results with your fat loss nutrition.

Here’s another one: “Men have an easier time losing weight.” I hear this comment several times each week. And for many reasons, it’s true. Men have less hormonal fluctuations and higher amounts of muscle mass. But there is another key factor – men tend to do less ‘extreme’ dieting. I grew up in a household full of women, wrestled in high school, and worked at a supermarket. As a result, I’ve seen almost every fad diet there is. The grapefruit diet, the cabbage soup diet, the juice diet, so on and so forth. And to be sure, people lose a significant amount of weight on these diets. But what if I told you that these diets can actually ruin your metabolism and make you fatter, even at a lower weight?

To illustrate this point, let’s examine a 2005 study by Layman, et. al. published in the Journal of Nutrition. They compared two diets: a low carb, high protein diet and a high carb, low protein diet. Both diets had a caloric deficit to cause weight loss. Each diet also had an exercise group and a sedentary group. Participants in each group lost significant amounts of body fat. However, both low-exercise groups also lost several pounds of muscle mass, on average.

The high-exercise groups retained more muscle mass, with the high-protein group keeping the most (1lbs lost on average, compared to a loss of 6lbs for the high carb, no exercise group). The high-protein and exercise group also lost an average of 20lbs of fat. That’s 9lbs more than the high carb, no exercise group with much less muscle mass loss!

So, what does this mean in metabolic terms? The less muscle mass you have, the slower your metabolism is. In this case, the high carbohydrate group lost plenty of weight but only 2% body fat. The high protein, high exercise diet lost over 5% bodyfat! Bear in mind that this was a scientifically designed diet with more protein than your average crash diet. It’s not uncommon for women on crash diets to actually increase their body fat percentage at lower weights because of how much muscle they lose! This is metabolic damage at it’s finest, and it can wreck your physique.

Let’s break this down into 4 key take aways:

#1 – High carb, low protein, low calorie diets without exercise cause you to lose very high amounts of muscle along with fat. This damages your metabolism and leads to a ‘skinny-fat’ appearance. This also makes it easier to get fatter once the diet ends.
#2 – ‘Dieting’ combined with exercise preserves muscle mass and metabolism.
#3 – High protein, low calorie, high weight lifting lifestyles and diets decrease fat, preserve muscle, and preserve metabolism. This makes it easier to maintain weight loss and look athletic.
#4 – To metabolically recover from crash diet damage, a diet higher in protein combined with weight training is recommended. On this program, you will actually gain weight as your restore your lost muscle mass. Your arms, legs, and stomach will look tighter, even as the scale rises.


Layman, Donald K., et. al. “Dietary Protein and Exercise Have Additive Effects on Body Composition during Weight Loss in Adult Women.” Journal of Nutrition 135.8 (2005): 1903-1910.http://jn.nutrition.org/content/135/8/1903.full.pdf+html