Iron Levels May Play a Role in Weight Gain

Written by Alexandria Nyembwe, PhD, MBA, RN | Reviewed by Katie E. Golden, MD

Published on January 13, 2025print_outlinedemail_outlined

Key takeaways:

Higher weight may lead to low iron levels. This is because increased body fat can cause inflammation in the body, which may make it harder for the body to store and use iron.
Iron deficiency may not directly cause weight gain, but it may contribute to weight gain in certain ways. Lower iron levels can lead to low energy levels, a slower metabolism, and a decline in thyroid function.
Researchers also suspect a link between higher weight and anemia (low blood counts), which may also be related to low iron.

Low iron & weight

Anemia & weight

Iron & weight loss

Symptoms

FAQs

Bottom line

References

A doctor holding a blood vial, talking to a patient. Artfully79/iStock via Getty Images Plus

Have you ever wondered if your iron levels could be affecting your weight? Recent research suggests that iron deficiency may affect up to 1 in 3 adults. And it seems to be more common in people with a higher weight. So could iron deficiency be one of the causes of weight gain?

Iron plays a major role in your body’s health, from keeping your energy levels up to helping your metabolism work smoothly. Iron is also a building block of red blood cells. So low iron can eventually lead to low red blood cell counts, a health condition called anemia.

Researchers are uncovering a complicated relationship between iron levels and weight. So, here, we’ll walk you through the connection between iron deficiency and weight and anemia and weight. And we’ll go over whether treatment for these conditions can help with weight loss.

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Can you have iron deficiency without anemia? Yes, and it’s surprisingly common. But many healthcare professionals don’t test for iron deficiency until it causes anemia.
Iron-rich foods: Learn the ways you can change your diet to increase iron intake and absorption.
How do you test for iron deficiency? Testing iron levels isn’t straightforward. And the best way to know may be to test something called a ferritin level.

Does iron deficiency cause weight gain?

Researchers have recently started looking into the connection between iron deficiency and weight. Scientists became interested in the link when they noticed that iron deficiency is more common in people diagnosed with obesity.

But does iron deficiency cause weight gain? Or does weight gain cause iron deficiency?

Based on the current research, it appears that higher weight can contribute to low iron levels. There are several different theories about why weight gain leads to iron deficiency. But it’s likely related to the way increased body fat increases inflammation in the body. And this inflammation may make it harder for the body to store iron.