In most cases, primary food production occurs in a process called photosynthesis, which is powered by sunlight. In a few environments, primary production happens though a process called chemosynthesis, which runs on chemical energy. Together, photosynthesis and chemosynthesis fuel all life on Earth.
Eat 5 â 7 servings of meat and beans per day. This depends on the total number of calories you consume in a day. 1  If you consume 1600 â 1800 calories, eat 5 servings per day. 2  If you consume 2000 calories, eat 5 Â½ servings per day. 3  If you consume 2200 calories, eat 6 servings per day. 4  If you consume 2400 â 2600 calories, eat 6 Â½ servings per day.
Most men from the age of 19 to 50 should eat about three cups of vegetables per day. Men over the age of 50 may only need about 2 1/2 cups. Men who get at least 30 minutes of exercise every day may need more vegetables. Women from the age of 19 to 50 need about 2 1/2 cups every day, while women over the age of 50 need about two cups. As with men, women who are physically active every day may need more.