We all know that it’s easy to meet the protein RDA on a vegan diet. But what constitutes “enough protein” remains a topic of some debate among experts.

Among its other functions, protein protects bone health which may in part be due to its effects on muscle mass. Unfortunately, a decline in muscle mass over the years is more common than not. It’s driven to some extent by hormones, but diet and lifestyle clearly have an impact on this, too.

Although weight-training is the most important way to build and preserve muscle, it gets a little bit harder to bulk up as the years pass–probably because protein is used less efficiently to rebuild muscle after exercise when you’re older. A new report from the International Osteoporosis Foundation (IOF) suggests that older adults may need as much as 1.0 to 1.2 grams of protein per kilogram of body weight, compared to the 0.8 grams that the RDAs specify. (For us non-metric-ly inclined Americans, 1.0 to 1.2 per kilogram translates to 0.45 to 0.54 grams per pound of body weight.)

Vegans may need to aim for the upper end of this range since protein digestion can be slightly lower from grains and legumes. It’s not especially difficult to meet those needs, but for some vegans it might require a little bit of a shift in food choices.

On the other hand, we vegans may have a distinct advantage, because protein is just one part of the muscle-preserving picture. The IOF report noted that acid-producing diets—those that are high in meat (and also grains)—can stimulate muscle breakdown. Because vegans typically replace meat with protein-rich legumes, our diets are likely to be less acid-producing. Eating lots of fruits and vegetables, especially those high in potassium, also prevents blood from becoming too acidic. And, it’s possible that the antioxidants in all plant foods—fruits and veggies especially, but also legumes—help reduce muscle loss according to the IOF.

This is kind of similar to the situation with calcium. Vegans may need to put a little more effort toward meeting calcium needs, but there is a decent tradeoff regarding nutrition. The plant foods that provide calcium also happen to provide many other compounds that are good for bones and that are not found in milk.

The issues that become important in later years—muscle and bone loss—can be avoided by good lifestyle choices in your younger years. Maintaining muscle mass is way easier than rebuilding it after it’s been lost. So, to keep muscles strong:

  • Do regular weight training. It’s the single most important thing you can do to build and hang on to muscle.
  • Emphasize legumes in your diet—beans, soyfoods and peanuts. In Vegan for Life, we encouraged at least 3 servings per day. I typically eat 4 to 5 servings. I know it sounds like a lot, but for me it translates to one cup of soyfoods (some combo of tofu, soymilk, and tempeh usually), one cup of beans, and 2 tablespoons of peanut butter.  I tend to favor legumes over grains.
  • The IOF suggested that vitamin D and possibly vitamin B12 are important for muscle health. Make sure you take at least 600 IUs of vitamin D every day and around 25 micrograms of B12. (You do this anyway, right?)
  • Eats lots of fruits and vegetables. They keep blood alkaline, provide antioxidants, and are also good sources of folate which may be important for strong muscles.