How Anemia Can Affect Your Weight

If you're struggling with your weight and also have fatigue, don't shrug it off. You might have anemia, a blood disorder. Anemia can make it frustratingly hard to control weight gain or loss and may also make it difficult to maintain a healthy weight. But there are steps you can take to help.

The blood disorder known as anemia has many forms, ranging from mild to serious. The condition involves having either too few red blood cells or damaged red blood cells, which makes your blood unable to get enough oxygen to the rest of your body, the U.S. National Library of Medicine says. Red blood cells contain a protein called hemoglobin, which carries oxygen from your lungs throughout your body. Anemia can leave you feeling tired.

Iron-deficiency anemia is a common form of the condition, the Mayo Clinic says. Another is vitamin-deficiency anemia. The risk for this kind of anemia rises with age, and pregnant people are also at risk because they require more vitamins, according to the Cleveland Clinic. Weight loss and fatigue are symptoms of vitamin-deficiency anemia, the Mayo Clinic says. These types of anemia can be treated, making it easier to control your weight.

The Mayo Clinic also lists more serious causes of anemia as including sickle cell anemia, kidney disease and Crohn's disease.

​Read more:​ The Difference Between Iron Deficiency Anemia & Vitamin Deficiency Anemia

When it comes to weight, anemia can be a double-edged sword. Anemia can make you so tired you are unable to exercise or be active, which can promote weight gain.

On the other hand, you may have an underlying condition that is causing you to lose weight, according to Douglas P. Jeffrey, MD, an Oregon-based physician. When this occurs, treatment of the underlying condition may help stabilize your weight. Not taking in enough nutrients can also cause you to lose weight.

Dr. Jeffrey notes that weight gain related to anemia has a lot to do with fatigue. "Because of the symptoms that develop with anemia, you might experience weight gain due to lack of normal activity," he says. "It's usually the effect anemia has on lifestyle that causes weight gain."

Dr. Jeffrey says you may also gain weight during treatment if you have iron-deficiency anemia, "but as blood and iron levels return to normal, you'll feel more energetic and will be able to become active and fit."

If you're trying to lose weight, having this condition can be incredibly frustrating. "Anemia stresses all of the organs, and makes burning fat much more difficult," says Caesar Djavaherian, MD, an emergency room physician based in San Francisco and co-founder at Carbon Health.

"Burning fat requires adequate oxygen, not to mention the fact that people feel weak and can become winded more easily if they don't have enough oxygen," he says. This makes exercising harder to do, and those fats, which store energy, can't be effectively mobilized to supply the body."

If you're troubled by weight loss, weight gain or any symptoms of iron deficiency, work with your doctor to determine the underlying cause and develop a treatment plan.

In some instances, modifying food intake may be a sufficient fix. "Just know that having anemia itself may not result in weight gain, but would reduce your chances of losing fat if no lifestyle changes are taken," Dr. Jeffrey says. "Ask your doctor to help you work out a balanced diet. Iron-deficiency anemia and vitamin-deficiency anemias can be avoided by having a diet that includes a variety of vitamins and minerals from meat, and lots of vegetables."

Taking iron supplements may also help, in some cases. "Most people get adequate iron from their diets, so supplements aren't needed," Dr. Djavaherian says. "However, if you're anemic because of heavy periods or bleeding from an ulcer, iron can't be replaced just by eating enough food. In those instances, taking supplements becomes critical to rebuilding red blood cells."

​Read more:​ Types of Iron Supplements