While you may think that meat and other protein sources are the only foods you need to build muscle, sports nutrition expert Clayton South explains that vegetables play a vital role as well. According to South, eating vegetables can increase energy efficiency and provide vitamins and minerals to aid in muscle contraction and dealing with oxidative stress. Vegetables that contain vitamins A, C, D and E as well as calcium and folate may be of primary importance for muscle building. In addition, because protein does provide the building blocks of muscle, you may also want to consume vegetables rich in protein.
Many bodybuilding supplements and protein bars include soy protein, which is created from protein-rich soybeans. While soybeans do contain some fat--three grams per half-cup serving, according to The Daily Plate--these vegetables also contain eight grams of protein per serving. In addition, The Daily Plate notes that soybeans provide four grams of fiber, which can keep you feeling full. The added satiety may prevent you from overeating, which can cause fat gain rather than lean mass gain.
According to Clayton South, consuming vegetables rich in vitamin E may benefit your attempts to gain lean mass. For this reason, you may want to include spinach in your mass-gaining diet. The online nutrition resource World's Healthiest Foods notes that spinach is one of the top sources of vitamin E. World's Healthiest Foods explains that vitamin E also prevents oxidative damage from free radicals, which can be created by exercise. Because building muscle requires intense workouts, the vitamin E in spinach may help your body recover, while the protein and carbohydrates can fuel your workouts.
Lentils come in a number of varieties and can be eaten alone, as a side dish, or as part of a soup or other recipe. According to the Vegetarian Resource Group, lentils are a good source of protein, with 18 grams of protein in each cooked cup. The Vegetarian Resource Group also explains that a 100-calorie serving of lentils contains 7.8 grams of protein, so even small portions of lentils can provide protein to help gain lean mass.
According to Clayton South, consuming calcium-rich vegetables may also help you gain lean muscle mass. Bayer HealthCare notes that broccoli is one of the top sources of calcium among vegetables, as one stalk of boiled broccoli provides 102 mg of calcium. In addition, the Vegetarian Resource Group notes that a 100-calorie serving of broccoli contains 6.8 grams of protein, which may also assist in lean mass gain.
Consuming black beans is another way to obtain some fat-free protein for building lean muscle. As the Vegetarian Resource Group explains, black beans provide 6.2 grams of protein per 100-calorie serving. Black beans also provide carbohydrates for energy and fiber to increase feelings of satiety.