"Calories Don't Matter on Keto!"
Wrong. Caloric intake above maintenance will still cause fat gain. One of the most misleading statements about keto diets is that calories don't matter as long as you're not consuming carbs.
This stems from the insulin-to-obesity theory. It goes something like this...
- Carbs cause insulin to be secreted.
- Insulin (the storage hormone) stores those carbs as fat.
- Eliminate carbs and you'll stop storing fat regardless of calories consumed.
- Become a fat-burning machine.
It's true that getting into a state of ketosis will increase fat oxidation. After all, fats and carbs are the main fuels used in the muscles for oxidation during exercise. If you eliminate carbs, then eventually the body is left with no choice but to use fat as the primary source for fuel. Boom! Increased fat oxidation, right?
But there's a difference in fat oxidation and a reduction in fat mass, which can only happen in an energy deficit. And if you're consuming an excess of calories from fat, then the body will do the same thing with those excess calories from fat as it does with carbs: it'll store them for later use.
The reason that a ketogenic diet works well for some people is that it can increase satiation – the feeling of fullness. This higher degree of satiation can naturally cause some to eat fewer calories, which leads to fat loss despite the fact that they may not be counting calories.
It's Just an Energy Deficit
The ketogenic diet will work for fat loss in the same way that every other diet works for fat loss – by creating an energy deficit. You cannot eat "as much as you want" on a keto diet and still lose fat simply because you eliminated a macronutrient source.
From the data we've seen, keto does appear to increase satiation better than most standard diets, which can help with dietary compliance and naturally reducing caloric intake. However, when calories and protein are equal, it's not a significant advantage for fat loss (1).
On the flip side, the keto diet falls flat on its face when it comes to increasing muscle (2) (3).
- Alan A. Aragon, et al. International society of sports nutrition position stand: diets and body composition, Journal of the International Society of Sports Nutritionvolume 14, Article number: 16 (2017)
- Vargas S, et al. Efficacy of ketogenic diet on body composition during resistance training in trained men: a randomized controlled trial, J Int Soc Sports Nutr. 2018 Jul 9;15(1):31. doi: 10.1186/s12970-018-0236-9.
- Wesley C. Kephart, et al. The Three-Month Effects of a Ketogenic Diet on Body Composition, Blood Parameters, and Performance Metrics in CrossFit Trainees: A Pilot Study. Sports (Basel). 2018, doi: 10.3390/sports6010001