By Mark Messina, PhD, Executive Director, Soy Nutrition Institute
When it comes to plant-based diets, both the amount and type of protein consumed matters. Soybeans score high on both metrics: they provide more protein and better quality protein than other plant foods, including other legumes.1
But there is another issue in protein nutrition than may be just as important. The pattern or distribution of protein intake throughout the day may matter for overall health. If it does, then most Americans need to shift their protein consumption habits to a more ideal pattern.
A few years ago, protein experts from the University of Texas Medical Branch concluded that the best approach for stimulating muscle protein synthesis (MPS) is to get 25 to 30 grams of protein three times a day.2 Muscle mass is lost during fasting states, which means that going too long between meals takes a toll on MPS. In particular, skipping breakfast can cause muscle mass to decline. So can eating a breakfast that is too low in protein. And that’s what many Americans, particularly older people, do. According to NHANES data, older Americans consume only about 11 grams of protein at breakfast.3
If you aren’t getting enough protein at breakfast, you can’t make up the difference later in the day. One 7-day study found that eating a moderate amount of protein at each meal stimulated 24-hour MPS in healthy adults to a greater extent than simply eating a lot of protein later in the day.4 In agreement, a newly published rat study found that MPS was significantly greater when each of the three meals contained 16% protein vs meals that contained 8%, 8%, and 27% protein.5
Protein distribution may be particularly important for older folks as it has been shown that aging is associated with an inability of skeletal muscle to respond to low doses of essential amino acids, whereas higher doses are capable of stimulating MPS to a similar extent as that of the young.6,7
It’s not as though Americans don’t like breakfast. Just look at the popularity of restaurants that serve “breakfast all day.” And it’s clear that even if the current protein RDA is too low, as some data suggest, with few exceptions Americans get plenty of protein.8,9
The key to maintaining optimal muscle mass throughout the lifespan isn’t more protein, it is evenly distributing the protein that is consumed throughout the day. For most Americans, that means ensuring that breakfasts are protein-rich. Soyfoods can help in this respect. Oatmeal or cornflakes with soymilk are quick and easy protein-rich choices. Scrambled tofu offers plenty of protein without the saturated fat found in eggs. When you’re in a hurry, a protein bar made with soy protein or a handful of soynuts makes a good breakfast-on-the-go.