1. net muscle growth = synthesis – breakdown
2. need =/= optimization
I’m totally cool with keto, honestly! but still don’t really like seeing stuff like the above graphic and people interpreting it to mean “KETO IS MUSCLE-SPARING.”
Keto isn’t muscle-sparing; the above graphic says nothing about net muscle growth. For that, you’d need to data on muscle protein breakdown, and preferably, an empirical measurement of actual hypertrophy. Synthesis is only half of the picture… and it doesn’t always favor keto… #context
For example, “Cumulative urinary nitrogen excretion was significantly greater and cumulative nitrogen balance significantly more negative, during treatment with the ketogenic than with the nonketogenic diet… Whole-body rates of leucine oxidation were significantly higher during treatment with the ketogenic than with the nonketogenic diet…” (Vazquez and Saimak, 1992).
And this: “Four hundred kcal carbohydrate per day had a greater protein-sparing effect than 400 kcal fat per day in obese women… We conclude that carbohydrate is necessary to spare tissue protein” (Bell et al., 1969).
As far as skeletal muscle growth is concerned, carbs and protein are more anabolic than dietary fat. I won’t argue that carb-restriction isn’t effective for fat loss in obese patients, especially if insulin resistance is present, because that simply isn’t true…
…although even this isn’t always the case (from Yang and Van Itallie, 1976):
Insulin is largely thought to reduce protein breakdown more so than promote muscle synthesis (eg, Gelfand and Barrett, 1987, Hillier et al., 1998, and Fukagawa et al., 1985). And you get way more insulin with carbs and protein (but really just carbs) than with dietary fat. Yes, there are some studies showing decent insulin spikes with whey, so the gym-bro’s might be able to slam protein shakes to get some of this benefit.
Can you build muscle on a low carb diet? Yes.
Do you need carbs to build muscle? No.
need =/= optimization
Sleep well, eat protein-rich foods, and perform resistance exercise = build muscle… but you’d probably build more muscle by swapping out some dietary fat for carbs (assuming isonitrogenous & isocaloric diets). That’s partly why things like the Targeted Ketogenic Diet and Carb Nite were developed.
Priorities? #context? Yes and yes (P<0.05).