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Is Iron Good For Weight Loss?

There are many supplements that supposedly help you lose weight. What about the essential mineral iron, does it play a role in weight loss?

The relationship between vitamins and minerals and weight loss is often interesting. If there is any relationship, weight loss usually comes from resolving an insufficiency or avoiding an excess intake of the vitamin or mineral.

This is the case with iron. Resolving an iron insufficiency may benefit weight loss slightly but more iron will not always lead to weight loss.

Iron insufficiencies are relatively common, especially in women, so even if it is just for the health benefits you may want to make sure you are consuming enough iron.

If you think you think your levels of iron may be insufficient you can get your levels measured to see if you should actively work on increasing your iron intake. Keep in mind that too much iron can cause serious negative side effects so it’s smart to talk to your doctor before heavily supplementing with iron.

How iron may help you lose weight

Vitamins and minerals play important roles in all kinds of processes inside of your body. If you don’t consume enough of these vitamins and minerals many of these processes take place in lesser or even zero amounts. This is usually bad for your health.

The opposite is also sometimes the case. Consuming too much of certain vitamins and minerals can cause negative side effects too.

Iron levels in particular may influence sleep quality (1). Quality sleep is very important when trying to lose weight.

More indirectly related to weight loss is that low iron can lead to things like worse exercise performance, weakness, and fatigue (2). These are likely not helpful when trying to lose weight which often involves working out and using some willpower.

In short, you want your iron levels to be at the right level. If this is already the case consuming more iron will likely not lead to weight loss. If your iron levels are low, consuming more iron may help with weight loss.

Iron insufficiencies are relatively common so you may want to make sure you are consuming enough iron.

It is hard to put resolving an iron insufficiency into a certain number of extra calories burned. For most people this will not be the lifestyle change that instantly gets them to their dream weight. However, together with the health benefits, making sure that your iron intake is sufficient may be worth it.

Iron daily recommendations

Below you can find a table with the recommended dietary allowances (RDA) for iron for adults, infants, and children (2).

There are two main forms of dietary iron: heme and nonheme. Plant-based iron is generally nonheme iron. Meats, seafood, and poultry contain both heme and nonheme iron.

The recommendations below are for nonvegetarians since heme iron from meat is more bioavailable than nonheme iron from plant-based foods. The recommendations for vegetarians are about 1.8 times higher.

Obviously, not all people have the same bodyweight, body composition, and activity levels. Hopefully one day there will be more specific dosage recommendations available. For now, these are some general intake numbers you can aim at.

AgeMaleFemalePregnancyLactation
0-6 months0.27 mg*0.27 mg*
7-12 months11 mg11 mg
1-3 years7 mg7 mg
4-8 years10 mg10 mg
9-13 years8 mg8 mg
14-18 years11 mg15 mg27 mg10 mg
19-50 years8 mg18 mg27 mg9 mg
51+ years8 mg8 mg
recommended dietary allowances (RDA) for iron | *Adequate Intake (AI)

As a first food example, cooked oysters contain about 7.8 mg iron per 100 grams (3). A plant-based food example is cooked lentils which contain about 3.3 mg iron per 100 grams (4).

People at risk of iron inadequacy

Some groups of people are more at risk of an iron inadequacy than others. Examples include (2):

  • Pregnant women
  • Infants and young children
  • Women with heavy menstrual bleeding
  • Frequent blood donors
  • People with cancer
  • People who have gastrointestinal disorders or have had gastrointestinal surgery
  • People with heart failure

If you are in one of these groups you may need to pay more attention to get an adequate iron intake.

Other people may want to talk to their doctors and get their blood levels checked first before heavily supplementing with iron to see if there is any need for it.

Iron deficiency symptoms

Iron deficiencies and inadequacies are not uncommon. Especially in the previously mentioned groups of people.

There are some symptoms that are associated with an iron deficiency. Experiencing these on a regular basis may be a sign that your iron levels are not optimal.

Some iron deficiency symptoms include (2):

  • Gastrointestinal disturbances
  • Weakness
  • Fatigue
  • Difficulty concentrating and impaired cognitive function,
  • Weakened immune function
  • Worse exercise and/or work performance
  • Worse body temperature regulation

Avoiding these iron deficiency symptoms alone may be reason enough to ensure that you are getting enough of this mineral.

Ways to get enough iron

In many cases it is luckily not that hard to increase your iron levels. This can be done both naturally with whole foods and supplementing.

Whole foods

Eating whole foods with iron in them is usually the most recommended way to increase your intake. The reason for this is the wide variety of additional nutrients you get.

Keep in mind that there are different types of iron. The iron from meats, seafood, and poultry will help you more than the same amount of iron in plant-based foods.

Some examples of foods with relatively high amounts of iron include:

  • Dark chocolate (70-85% cacao): about 11.9 mg per 100 grams (5)
  • Oyster (cooked): about 7.8 mg per 100 grams (3)
  • Beef liver (cooked): about 6.2 mg per 100 grams (6)
  • Lentils (cooked): about 3.3 mg per 100 grams (4)
  • Sardines (canned): about 2.9 mg per 100 grams (7)
  • Chickpeas (cooked): about 2.9 mg per 100 grams (8)

When you know what foods to focus on it becomes a lot easier to reach your daily recommended intake for iron. Besides these examples, you can find amounts of iron in a wide variety of foods.

Dietary supplements

The next option to increase your iron intake is by taking dietary supplements. These are pills, capsules, tablets, or liquids with concentrated quantities of iron.

While supplementing iron can be helpful in certain situations too much iron can also cause negative side effects. That’s why it may be smart to talk to your doctor before heavily supplementing. At least keep a close eye on the dosage of the supplements and how much iron is already in your diet.

Can you consume too much iron?

One thing you do have to keep in mind is that you can also consume too much of certain vitamins and minerals. This is called the tolerable upper intake level, the highest level of nutrient intake that is likely to pose no risk of adverse health effects for almost all individuals in the general population (9).

There are tolerable upper intake levels established for iron. This means that having too much iron can cause adverse health effects. These are currently the tolerable upper intake levels established for iron (2):

AgeMaleFemalePregnancyLactation
0-6 months40 mg40 mg
7-12 months40 mg40 mg
1-3 years40 mg40 mg
4-8 years40 mg40 mg
9-13 years40 mg40 mg
14-18 years45 mg45 mg45 mg45 mg
19+ years45 mg45 mg45 mg45 mg
Tolerable Upper Intake Levels (ULs) for iron

If you stick to whole foods it is unlikely that you go over the tolerable upper intake levels for iron. When supplementing you certainly want to keep these in mind since overdoing it with iron can have serious side effects.

It’s smart to talk to your doctor before heavily supplementing with iron.

Conclusion

Implementing more iron into your diet or supplementing may help with losing weight if your iron levels are currently too low. If your iron levels are already normal, adding more iron will likely not cause weight loss.

Iron insufficiencies are relatively common, especially in women, so even if it is just for the health benefits you may want to make sure you are consuming enough iron.

There are daily intake recommendations you can aim for but ultimately the ideal iron intake for you personally also depends on how well you absorb it, what sources of iron you choose, and other lifestyle factors.

Because there are tolerable upper intake levels you also don’t want to consume too much iron. This can cause serious negative side effects. Before drastically increasing your iron intake it may be smart to talk to your doctor first.

Exactly how many extra calories you will burn by resolving an iron insufficiency is not clear. This will likely not be the thing that gets you to your dream weight. Even so, together with the other health benefits making sure that your iron intake is sufficient may be worth it.