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Q. I’m thinking about going vegetarian to lose weight. But I’m concerned that I may be lacking in nutrients to sustain my regular workouts. Is it true that it’s hard to get enough protein on a vegetarian or vegan diet?

A. Absolutely not. In fact, it’s easy to get enough protein, as well as other essential nutrients, from a plant-based diet no matter which end of the spectrum you are on: a vegetarian or a vegan. (Vegetarians eat dairy products but no fish, meat or poultry, while vegans don’t eat dairy, fish, meat or poultry.) A 2009 statement by the American Dietetic Association says that both vegetarian and vegan diets are “healthful, nutritionally adequate and may provide health benefits in the prevention and treatment of certain diseases” if they are “appropriately planned.”

The operative phrase here is “appropriately planned”—but this caveat applies to all types of diets. Even meat-eaters can miss out on important nutrients if they fail to eat the range of foods needed to meet their nutritional requirements. In fact, the typical eater, an omnivore, is more likely to be lacking. A 2003 survey published in the journal Preventive Medicine looked at a representative sample of the U.S. population—more than 15,000 American adults—and found that only 35 percent ate the minimum recommended amount of five or more servings of fruits and vegetables per day.

Veggie types are likely to eat better than most, since they tend to be food- and health-conscious. While even a vegan who eats well is going to have no problem getting enough protein, a vegetarian who eats dairy products is very unlikely to be lacking protein. So why do so many people think vegetarians can’t get enough protein?

One simple reason: Many people misunderstand what protein is. They refer to animal foods as “protein” and use the term as if it’s a food group, rather than a component, along with other nutrients, of all different types of foods. To really understand what protein is and where you can get it, let’s review the basics. Bear with me; this gets a little scientific, but once you understand it, you’ll have a deeper understanding of nutrition.

The macronutrients
Foods contain macronutrients. The three major macronutrients are protein, fat and carbohydrates, and they all provide calories, or energy, to the body. (Micronutrients are vitamins and minerals that help cells to function, but do not provide calories.)

What’s in a food
Almost all foods contain at least two macronutrients. A bean, for example, contains protein, fat and carbohydrates. A vegetable or a grain contains protein and carbohydrates. A fruit contains carbohydrates and (surprise!) some protein. Some fruits, such as an avocado, may also contain fat. Meat contains protein and fat, as do eggs. Nuts contain protein, fat and carbohydrates.

Some foods consist of one macronutrient only. For example, butter, which is made from protein-, carbohydrate- and fat-containing milk, is pure fat. So are oils, which come from protein-, carbohydrate- and fat-containing plant sources such as olives or walnuts.

The nitty-gritty
But that’s not the whole story: These broad categories are blanket terms and break down even further. There are a number of different kinds of fats (saturated and unsaturated fatty acids) and carbs (starches and sugars).

Protein actually refers to the wide variety of groupings of amino acids found in foods and in the body. So there is not just one thing called “protein”; it’s a blanket term, and there are many different kinds of proteins, or grouping of amino acids. The body makes most of them itself with its existing supplies of amino acids.

But there are a handful of amino acids that the body needs but does not make. These “essential amino acids” must be supplied by what you eat. They are: tryptophan, valine, threonine, isoleucine, leucine, lysine, phenylalanine, methionine and histidine.

Essential amino acids and ‘complete’ protein
The difference between animal foods and plant foods that contain protein is that the animal foods tend to have all of the essential amino acids in one bite, whereas most plant foods contain some, but not all, of the essential amino acids in one bite. That’s why animal foods are called “complete” protein.

The thing is, there’s no proof that we need to get all of our essential amino acids in one bite. In fact, if you eat a healthful, varied vegetarian or vegan diet, you can easily get all of your essentials. The American Dietetic Association notes that a vegetarian or vegan who eats an assortment of plant foods over a day can get all of the essential amino acids. It used to be believed that plant foods had to be combined and eaten at the same time (peanut butter on bread or rice and beans in the same meal, for example). Now it’s known that the different essential amino acids only need to be consumed within the same day or so to be available to the body.

So you probably don’t need to worry about protein. But make sure to eat a wholesome, varied diet full of nuts, beans, whole grains, fruit and vegetables. For more information, especially about sports nutrition for vegetarians, check out the “Vegetarian Sports Nutrition.”

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