No Vegetable Diet

Crash diets that eliminate entire groups of foods, such as carbohydrates or vegetables are problematic. The U.S. Department of Agriculture redesigned its well-regarded My Food Pyramid a few years ago to include vegan and vegetarian versions as well as gender- and age-appropriate ones. Each My Food Pyramid includes the recommendation of eating fresh vegetables daily for soluble and insoluble fiber, water content and vitamins and minerals. Eating a diet that excludes vegetables also excludes those nutritional benefits.

Incomplete Nutrition

• Once fashionable fad diets that focused on eating a high protein diet with few, if any, carbohydrates soon fell out of vogue. It is hard to eat only protein, much less only protein and vegetables with an occasional fruit.

  Your body needs consistent replenishment of a variety of amino acids, which it gets from the various proteins you eat. If you get all of the amino acids the body needs, you are consuming what are known as "complete proteins."

  Eating beans and rice serves as a complete protein, but you must eat them together to achieve completion. Eating fish, eggs, poulty, meat or dairy foods can give you complete protein consumption in a single package.

  Eliminating vegetables completely means you will have to eat fruits and other high fiber foods to move the heavy protein of meats and dairy foods through your digestive tract. Vegetables have valuable soluble and insoluble fiber that acts as an "intestinal broom" to keep your colon clear and reduce the risk of colon cancer.

Danger of High Protein Diets

• Eating a diet that draws more than 30 percent its calories from protein daily without including fiber can lead to constipation. Eating a very high protein diet can lead to ketosis. The National Institutes of Health states that having too many ketones in the tissues can lead to a complication of diabetes known as mellitus.
  Most people need to consume a total daily protein amount that equals half their body weight in pounds times 1g. For example, a woman weighing 140 lbs. might need only 70g of protein daily. Athletes might bump that up to 0.8g per pound of body weight.

  If you are eating a very high protein diet, ask your doctor about it: she may advise you to drink very large quantities of water or other advice.

How Many Vegetables Per Day?

• My Food Pyramid recommends that healthy adults eat four to seven 1/2-cup servings of vegetables a day. In one meal, fill half your plate with two to three kinds of vegetables. Doing so will ensure you get adequate fiber and important vitamins and minerals. For example, broccoli and dark green leafy vegetables like kale, provide calcium.