Women Will Benefit From Eating More Protein by Joan Kent, PhD

Women Will Benefit From Eating More Protein
By Joan Kent, PhD

Some years ago (1997 to be exact), the American Journal of Clinical Nutrition featured an article stating that women’s protein needs had been underestimated up until then.

In the same issue, a different article discussed the higher rate of serotonin turnover in women’s brains versus that of men. (Serotonin is made from the amino acid tryptophan. Amino acids are the building blocks of protein.) So women need protein for that reason.

The same year, Smith et al. published a study in the Lancet describing the relapse of depression in susceptible women after rapid depletion of tryptophan.

It’s a long-held theory of mine that people who minimize the importance of dietary protein don’t recognize the need for what I call “brain protein.” And it turns out that protein is now being evaluated and declared important for several other reasons, some of them of specific concern to women – weight loss, satiety, lean body mass, athletic performance, and more.

• In 2012, adult protein requirements were assessed as 10% higher than previously assessed, for both men and women and all age groups (Millward, 2012).

• A 12-week weight loss study in overweight adults showed that higher protein intake promoted better retention of lean body mass in both trunk and legs (Tang et al., 2013).

• Maintaining adequate protein intake with aging may help preserve muscle mass and strength in adult men and women. Type of dietary protein may affect muscle mass and strength differently. Animal protein promoted higher lean leg mass with higher intake, while plant protein did not (Sahni et al., 2015).

• Older women in the higher protein group (1.1g/kg/day vs. 0.8g/kg/day) had lower body mass index and lower fat-to-lean ratio than those in the lower protein group. The lower protein diet also resulted in impaired strength in both upper and lower extremities (Gregorio et al., 2014).

• Even distribution of protein intake – approximately 30g of protein per meal – stimulated muscle protein synthesis more effectively than the typical pattern of skewing protein toward the evening meal, with a breakfast higher in carbs and lower in protein (Mamerow et al., 2014).

• A recent seminar on protein’s role in weight loss and satiety, offered by the American Council on Exercise, also recommended a protein pattern of 30 grams per meal, 3 times a day.

• Two studies indicated a need for increased dietary protein intake so that the so-called “nutritionally non-essential amino acids” would be adequate for animals and humans to achieve optimal growth, reproduction and resistance to metabolic and infectious diseases (Hou et al, 2015; Wu et al, 2013). Essential amino acids are not synthesized by the body and must be consumed in food. Non-essential amino acids are traditionally assumed to be adequately synthesized by the body for maximal growth and health. These two studies counter that assumption.

• Female football players have protein needs similar to those of male players (Maughan and Shirreff, 2007).

• Women strength athletes may require more protein than either endurance-trained or sedentary women. The recommendations call for less emphasis on high-carb intake and more emphasis on quality protein and fat consumption to enhance training adaptations and general health (Volek et al, 2006). Compared to men, women seem to be less reliant on glycogen during exercise and less responsive to carb-mediated glycogen synthesis during recovery.

• Minimum protein intakes should be approximately 25% of total calorie intake (Fulgoni 2008). Many adults, men and women, get only 15% of their energy intake from protein.

• In a 12-week study, a daily high-protein (35g) breakfast prevented gains in body fat. A “normal” protein breakfast did not. The high-protein breakfast reduced hunger and led to voluntary reductions of about 400 calories per day (Leidy, et al 2015).

Regarding the long-touted RDA of 0.8g protein/kg/day, Stewart Phillips, PhD, FACSM, FACN, and professor at McMaster University states, “nothing about that level should be recommended, and you’re allowed to eat much more. In fact, for older persons and athletes, there are benefits to consuming protein at levels above the RDA.”

Indoor cycling instructors, for example, are athletes, and regular participants may be, as well. If you work out hard and often, be careful not to underestimate your protein needs.

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