Alternate High Protein Days & Low Protein Days to Drop Fat & Build Muscle

DeLauer presents this protocol as a practical application of the protein sensitivity concept. He reasons that if constant protein intake might blunt the muscle-building signal, occasional low-protein days could act as a 'reset.' During the low day, mTOR is suppressed, autophagy ramps up, and the body may upregulate amino acid recycling to spare muscle. When high protein is resumed, the surge in mTOR, IGF-1, and testosterone responsiveness drives a super-compensatory anabolic rebound, leading to greater net muscle protein synthesis than if protein was kept uniformly high. He supports this with the bolus-study evidence that longer gaps between protein feedings increase aggregate muscle protein synthesis, and with intermittent fasting research showing muscle preservation despite reduced calories and lower anabolic hormones. He personally implements this by dropping from 200-300g down to 50g on select days, noting it also feels good digestively.

DeLauer argues that the fitness world pushes constant protein consumption, but that like with carbohydrates, taking a break could make the body respond more robustly when protein is reintroduced. He draws parallels to how calorie or carb restriction improves insulin sensitivity and glucose tolerance, citing a 1969 Lancet study showing starvation increased glucose tolerance independent of weight loss. He hypothesizes that if prolonged fasting leads to better fuel utilization, then short protein breaks could lead to better protein utilization, triggering an 'anabolic rebound' with surges in testosterone, IGF, and mTOR activation. He ties this to the observed muscle sparing in intermittent fasting studies, where despite lower total calories and even decreases in anabolic hormones, muscle mass is preserved, likely due to heightened sensitivity upon refeeding. The concept is new and speculative but backed by studies on alternate-day fasting, intermittent caloric restriction, and bolus protein feeding patterns.

DeLauer reviews multiple studies: an alternate-day fasting study (Nutrition Journal) where subjects ate 25% of calories one day and ad libitum the next, losing more weight but no muscle loss compared to controls; an intermittent caloric restriction study where fluctuating low and high calorie days preserved more muscle than steady restriction while losing equal fat; and a time-restricted feeding study (Translational Medicine) showing TRF subjects preserved muscle mass despite lower testosterone and IGF, suggesting heightened anabolic sensitivity. He interprets these as evidence that the body adapts to brief restriction by improving its ability to retain protein when it is available again, a 'muscle sparing' effect that may be the result of protein sensitization and anabolic rebound.

DeLauer describes a Physiology journal study where participants after resistance training consumed 80g protein total, divided into three groups: 10g every 1.5 hours, 20g every 3 hours, or 40g every 6 hours. The bolus group (40g every 6h) showed the highest aggregate muscle protein synthesis markers (mTOR, p70S6K phosphorylation) over the study period. He argues that the longer gap between meals may have resensitized the muscle to the anabolic signal, and the bolus then triggered a stronger mTOR activation — a 'mTor priming' effect. This supports the idea that occasional protein restriction between larger feedings can maximize anabolism, rather than constant nibbling.

DeLauer explains that decreasing protein inhibits mTOR, which upregulates autophagy. This clears cellular debris, potentially makes cells operate more effectively, and promotes the reutilization of amino acids — broken down proteins from one area are redirected to more critical areas, sparing muscle. He notes that this approach aligns with concepts from Dr. Valter Longo's fasting-mimicking diet, which uses low protein and higher fat to stimulate autophagy while still providing energy. An mTOR rebound upon reintroducing protein could further boost anabolic signaling. This provides a rationale for occasional low-protein days as a 'protein fast' rather than a complete fast.