Protein Research
This is a compilation of research I did that didn’t necessarily make it into the summary.
Studies show most people only consume about 75% of their daily protein. This aligns with my own experience. When reviewing the diets of a majority of the clients I train, they are often deficient in calories and protein.
Most studies conclude around 1.4-2.0 g/kg of bodyweight per day (1 lb = ~2.2 kg).
A commonly expression, mostly among bodybuilders, is to consume 1 g per 1 lb of bodyweight. That’s easy to remember, but there is no positive proof that a diet consisting of more than 2.0 g/kg BW/day of protein will increase lean mass.
In the United States, the Recommended Daily Allowance (RDA) for protein is 0.8 g per kilogram of body weight (0.36 g/lb/day), but more recent research suggests that 1.2 g/kg (0.54 g/lb) is a safer minimal daily intake for sedentary adults wishing to maintain muscle mass without losing or gaining weight, whereas people with fitness goals can benefit from 1.4–2.0 g/kg/day.
Consume 20–40 g of protein per meal, starting with breakfast.
Consume 20–40 g of protein within the 2 hours preceding or following your workout to help stimulate muscle growth. If you take your protein after your workout or within the 30 minutes leading to it, favor a protein that digests quickly, such as a whey protein concentrate.
Consume 20–40 g of protein before bed to help stimulate muscle growth (or at least reduce muscle breakdown) while you sleep. A protein that digests slowly, such as micellar casein, should be ideal at that time.
As we age, our muscles can develop a resistance to dietary proteins’ anabolic signals. Larger doses can partially compensate for this resistance, so if you’re over forty, aim for the higher half of the above ranges — i.e., aim for 1.7–2.0 g/kg/day (0.77–0.91 g/lb/ day), including 30–40 g per meal, before bed, and either before or after your workout.
The protein you ingest is digested into amino acids, which are then recombined as muscle fibers, among other things. Some amino acids (chiefly leucine) are especially important for muscle growth.
A higher protein intake does not seem to have negative health effects in people without kidney issues. Anyone with pre-existing medical conditions, consult your doctor, ideally an RD (registered dietician).
Whey protein and casein powders are both derived from milk protein (which is 20% whey and 80% casein). Whey protein digests quickly, whereas micellar casein digests slowly, so a case could be made for drinking the former around your workout (to quickly feed your muscles) and the latter before bed (to keep your muscles fed overnight). If you’d rather buy only one type of protein powder, milk protein isolates are available, but a whey protein concentrate that is at least 80% protein will be much cheaper and the best bang for your buck.
If you are lactose intolerant or vegan you can still supplement protein powders. Whey protein isolates contain very little lactose. For vegans, two popular options are soy protein, a complete protein, and a 70:30 pea:rice protein blend, which is seen as the vegan alternative to whey protein due to their similar amino acid profiles.
Protein consumed at 2.0g/kg BW per day in conjunction with heavy resistance training a positive nitrogen balance could be maintained by a strength athlete (Celejowa et al., 1970; Laritchevia et al., 1978).
At 3.3g/kg BW/day the athletes had notable increased in protein synthesis and added lean body mass. But they also experienced amino acid oxidation which suggests that the additional protein was excessive and exceeded the maximum requirements for muscle growth. In a study (Tarnopolsky et al 1992) that compared 1.4 g/kg to 2.4 g/kg BW found that the additional protein did not increase protein synthesis but did increase amino acid oxidation. The excess protein is used for energy.
The protein ingestion for strength athletes should be between 1.4-1.8 g/kg BW/day. Protein needs are decreased with training experience and that the lower end of the recommended range be used with an experienced athlete.