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Amino Acids: Why Don’t I Have Enough?

The four reasons why so many people are deficient in amino acids

If you continually fight cravings for sweet and starchy foods, your appetite might be out of control because you’re low in certain brain chemicals. You may not have enough of the brain chemicals that are made from amino acids to make you feel emotionally strong and satisfied.

Each of the neurotransmitters that support brain health is made from prortein building blocks called amino acids. These are basic nutritional elements produced within our bodies or ingested through the food we eat. If you lack these important substances, you may feel depressed, tense, irritable, and hungry all the time.

If our bodies produce some of the amino acids we need and we ingest others, why do so many people lack the necessary amino acids to help regulate appetite? This is a very important question to answer.

Several factors contribute to amino acid deficiency:

1. Lack of Protein

The primary cause is insufficient protein. Protein is absolutely necessary for the body to make amino acids. And because amino acids are not stored for very long, people need to eat enough protein every day. Both animal-and plant-based foods contain amino acids, but only animal foods contain all of the essential amino acids. Some animal-based foods rich in amino acids are meat, turkey, chicken, eggs, milk, cheese, and yogurt. All of these are high in protein. It is from the breakdown of protein in our digestive systems that the body can access the amino acids it needs.

Dietary Guidelines for Americans, the U.S. government’s nutritional advice for Americans was revised in 2010. One of the major changes in this version was this recommendation: Increase consumption of protein.

People who get most of their calories from sweets and starches are likely to be deficient in protein. In addition, vegans and vegetarians are often protein-deficient. They need to eat a variety of legumes, nuts, seeds, grains, and vegetables every day in order to obtain all of the essential amino acids.

Adolescents, who tend to subsist on a diet of pasta, are at greatest risk of amino acid deficiency. Young people who struggle with disordered eating are of special concern and should be tested to make sure that amino acids as well as minerals and vitamins are at sufficient levels.

2. Poor digestion of protein

It’s sometimes not enough just to eat more protein. Protein must be broken down into its constituent parts before it is of any use. A second cause of a deficiency can be poor protein digestion. Sometimes people have inherited biochemical anomalies that limit their bodies’ ability to break down protein.

In other cases, insufficient protein digestion comes from a lack of hydrochloric acid. The breakdown of protein occurs in the stomach, which secretes the powerful gastric acid called hydrochloric acid. Hydrochloric acid converts a substance called pepsinogen into pepsin, an enzyme that cuts up protein into smaller pieces known as polypeptides. In a sense, hydrochloric acid takes the “dull” pepsinogen and turns it into the “razor-sharp” pepsin. Without pepsin, the human body cannot digest protein, so a decrease in the production of hydrochloric acid means that protein digestion will be less efficient. Too little hydrochloric acid translates into decreased nutrient absorption as well as impaired signals to the brain that the belly is full.

3. Aging

Insufficient amino acid levels can also result from the aging process. As we age, stomach acid levels decrease. Stomach acid drops by almost 40% from the teens to the thirties and almost half again by the seventies. Consequently, our ability to digest protein diminishes with age.

Of course we can’t help aging, but there are things we can do to help sustain our bodies’ protein synthesis. Getting enough sleep, avoiding stress, exercising regularly, and eating a diet rich in protein can all help.

4. Antacid Use

The fourth cause of low amino acid levels is antacid use. Millions of people who experience stomach discomfort and develop indigestion from overeating treat themselves with antacids. Taking antacids actually makes the problem of overeating worse. People trying to medicate their discomfort may unwittingly exacerbate problems with protein digestion by reducing their already low levels of hydrochloric acid even further. As stomach acid in fact helps control appetite, decreasing levels can reinforce disordered patterns of eating.

If you have stomach problems, heartburn, gas, bloating, or other digestive complaints, and depressed mood, your problems might be caused by low levels of stomach acid, resulting in deficiencies in amino acids.

Despite the potential harm antacids can cause to your body, it is important to taper off antacids gradually rather than stopping all at once.

Because low levels of amino acids are a very frequent culprit in disordered eating, and because low levels are very common, I encourage you to have your amino acid levels tested. Both the tests and the treatment are simple, safe, and inexpensive. One intervention—supplementation with amino acids—can make a tremendous difference in your ability to control your appetite.

In the next post in our series, I’ll tell you more about some of the individual amino acids. Of the 20 of them, some are more important to appetite than others. . .

Spotlight on:

Julia Ross. (2012). The Diet Cure. New York: Penguin.

Dietary Guidelines for Americans.(2010). Center for Nutrition Policy and Promotion, U.S. Department of Agriculture, @

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