Inverse Carb Leverage HypothesisTM
Protein Leverage Hypothesis: Dude eats 15% protein on a 2000 kcal diet (75 g protein). Exchange 25 grams of protein with carb, and he’s now eating 10% protein on a 2000 kcal diet (50 g protein). Theory states Dude will increase total food intake to get back those 25 grams.
Ergo, Protein Leverage Hypothesis:
Disclaimer: I don’t care much for the Protein Leverage Hypothesis. It might be true, but that doesn’t mean it matters. It works well in rodents, but obese patients eat tons of protein. The rebuttal to this is that the protein in their diet is too diluted with other [empty] calories. They’re overeating because of low protein %.
The flipside, confirmed ad nauseam in rodent studies, is that frank protein deficiency increases food intake. Frank protein deficiency means negative nitrogen balance & tissue loss… not just skeletal muscle; organs, too. Incompatible with survival.
Feed someone a low protein low fat diet, they get hungry. If it’s ad libitum, they eat more.
Dr. Gosby’s recent study, the one that made waves, was not good. I’ll discuss the much better one she did in 2011. In brief, lean healthy people were given one of 3 ad lib diets for 4 days containing 10, 15, or 25% protein (all 30% fat). Most of the meals in each group had a roughly similar macronutrient profile and looked like prison food:
10% protein group did indeed “leverage” protein… to reclaim a whopping 7 grams #fail
The 10% protein group was also the 60% carb group. They ate the most. The 15% protein group was the 50% carb group. Going from the 15% to the 10% group was supposed to increase carbs by 26 grams (had no leveraging occurred). But it increased by 39 (a 13 gram overshoot). Protein Leveraging *makes sense* from a biological perspective, but these data suggest Inverse Carb LeverageTM is stronger.
It’s a small [weak] effect, but here are 2 more examples.
First one: obese kids that stopped drinking regular soda reduced their calorie intake and lost weight. Yeah, they weren’t getting soda calories so duh calorie intake declined. But calories declined by more than just the soda calories. They stopped drinking soda which made them eat fewer chips.
Second one: NHANES. Kids who drank more soda had higher calorie intake. Duh liquid soda calories aren’t compensated for. But it gets better (worse): the increased calorie intake was above and beyond those attributable to the soda calories. Inverse Carb LeverageTM
These differences were all quantitatively small, but obesity doesn’t happen overnight.
Alternate conclusion: I think the Inverse Carb LeverageTM is as strong as the Protein Leverage Hypothesis, which isn’t very strong.