Meals under 600 calories must include a source of lean protein, vegetables and a source of healthy fat. The meal can include as many vegetables as wanted, as long as they are consumed raw or steamed, not fried in oil, according to Health Ambition.
Some of the best vegetables to include in meals under 600 calories include leafy greens, such as spinach, asparagus and broccoli. Some of the best sources for lean protein include chicken without the skin, tuna, turkey breast and white fish. For healthy fats, some of the best options include almonds, salmon, avocado and flax, notes Health Ambition. On occasion, some whole grains are also fine to allow into meals under 600 calories, including brown rice and quinoa.