“A lot of plant foods are really filling, which can be a good and bad thing,” says Ryan D. Andrews, CSCS, registered dietitian based in Norwalk, Connecticut, and author of A Guide to Plant-Based Eating. Since plants are often low in calories but high in fiber, they can make you feel full more quickly.
This benefits you if you’re focused on fat loss, but otherwise, it can lead to drops in weight and muscle, he notes.
If you feel symptoms of under-eating like lethargy and mood swings, you might want to consider adding one serving of healthy fats, the highest-calorie macro, to each meal and snack. Try a tablespoon of olive oil (120 calories), a quarter cup of walnuts (190 calories), or two tablespoons of chia seeds (139 calories).
Animal foods like eggs, poultry, and dairy are sometimes referred to as complete proteins because they contain all nine essential amino acids. Plants, on the other hand, are relegated to the incomplete protein group, since they typically lack at least one. Nutrition experts, however, argue that those classifications are BS.
The essential amino acids are important because they help your body build muscle, tissues, and more. But the claim that vegans can't get them all is unfounded, Caspero says. As long as you eat a variety of plant foods, you'll easily meet the daily requirements.
If there's one amino acid that is harder for vegans to get, it's lysine, which encourages muscle repair and the collagen production needed for healthy joints. It's mostly found in ingredients like skirt steak and chicken breast. Plant-based athletes can find their daily dose in two or three servings of legumes or soy products like tofu or tempeh.
One vitamin that's impossible to get from whole, vegan foods is B12. Clams are a top source, but almost all meat has some. The nutrient is important for brain health, so all vegans should take a daily supplement, says Drew Ramsey, MD, founder of the Brain Food Clinic and assistant clinical professor of psychiatry at Columbia University in New York City.
Choline, on the other hand, is found in some plants—but to reach the daily recommended intake, you'd need to eat about seven cups of Brussels sprouts or broccoli. The longer you exercise, the more your body gets depleted of this nutrient, making it especially important for endurance athletes. When your stores are low, you're more likely to feel mid-workout fatigue and post-workout soreness. For vegans, a supplement is in order.
Vegans don't need to supplement their diets with bars and powders to get enough protein, Caspero says. Large-scale research shows that most Americans actually eat twice as much of the macro as they need.
The International Society of Sports Medicine recommends athletes consume at least 20 grams per meal. Hitting that minimum encourages your body to build and repair muscles after they've been damaged during workouts.
At breakfast, you can get there with half a cup of oatmeal made with one cup of soy milk, one tablespoon of peanut butter, and one tablespoon each of chia and hemp seeds. At lunch or dinner, make a spinach salad with three ounces of tempeh and dressing made with a tablespoon of tahini or olive oil.
FODMAPs are a class of fermentable carbohydrates that include fructose, lactose, fructans, galactans, and polyols. In some people, they contribute to digestive issues because they’re difficult to break down. They’re particularly hard to avoid on plant-based diets.
To minimize mid-workout GI issues like gas and bloating, skip high-FODMAP foods like onions, garlic, chickpeas, Brussels sprouts, cauliflower, apples, and figs for at least two hours before working out, Andrews says.
Making this mistake can lead to the belief that a plant-based diet isn't right for you, he notes—even when it can be a positive change.