Does iron deficiency cause weight gain?

Despite iron being found in a range of foods, many of us can find ourselves battling with iron deficiency.

Whether it’s a result of diet, hormones, or various health factors, depleted iron stores can leave us feeling sluggish with low energy and lack of concentration. But for those who are experiencing such symptoms, can iron deficiency cause weight gain? 

To see sustainable weight loss results, you need to approach your health holistically. Rather than drastically reducing your calorie intake and finding yourself perpetually hungry, you want to focus on a healthy, balanced diet and increasing your activity levels with exercise.

For those who are iron deficient, however, the latter can be difficult. When you’re already feeling weak and fatigued, it’s easy to find yourself lacking all motivation to exercise which can lead to weight gain.

If you’ve experienced sudden weight gain and are wondering if iron deficiency might be to blame, you’ve come to the right place.

Here, we break down everything you need to know about iron deficiency from its causes to symptoms and the top iron-rich foods you should be adding to your plate. Let’s dive in!

Why is iron important for your health?

Iron is a mineral that’s crucial for optimal health, as well as muscle growth and development. It plays a crucial role in transporting oxygen in the blood and is also used to make some hormones.

While iron intake needs will vary depending on factors like age, sex, diet, body mass index (BMI), and activity levels, the NHS for iron is 14.8mg/day for women aged 19-49 years, 8.7mg/day for women aged 50 or over, and 8.7mg/day for men aged 19 years and over [1].

The importance of iron for optimal health can’t be overstated. It plays a key role in the body, including the following:

• Oxygen transport: Iron is essential in making hemoglobin, which is a protein found in red blood cells. These red blood cells help carry oxygen throughout the body from the lungs. Similarly, iron is also found in myoglobin, which is a protein found in muscles that is used to store oxygen. Roughly 70% of iron in the body is found in hemoglobin and myoglobin, with the latter supporting muscle growth and body development. 
• Healthy immune system: As well as supporting good health and vitality, iron also helps with the normal function of your immune system.  
• Healthy pregnancy: During pregnancy, blood volume and red blood cell production increase in order to supply the foetus with oxygen and essential nutrients. This places a greater demand for iron for women who are pregnant, and low iron intake during this time can increase the risk of premature birth and low birth weight.
• Cognitive function: Iron is essential for brain metabolism, with studies finding that a deficiency can cause changes in neurotransmitter homeostasis, leading to a decline in cognitive functions [2]. Not surprisingly, iron is essential for mental performance and supports attention span, reasoning, and decision-making.

How do your iron levels impact your weight?

While iron deficiency anaemia doesn’t directly affect your weight, the health issues that arise from low iron levels can contribute to weight gain.

Most notably, decreased oxygen to organs and tissues can lead to symptoms like fatigue, shortness of breath, and low energy levels. 

When you’re struggling with such symptoms, engaging in physical activity is often furthest from your mind, which may lead you to be sedentary. This lack of exercise can contribute to weight gain, particularly when you’re not entering a caloric deficit in terms of food consumption. 

However, it isn’t just weight gain that low iron can contribute to.

In some cases, iron deficiency anaemia can lead to a decrease in appetite or a change in taste. Those who experience this often report a decrease in food intake, leading to weight loss. Some people have also pointed fingers at the treatment of iron deficiency, saying it leads to weight gain. However, research has shown the opposite, with treatment inducing weight loss [3].

Can low iron cause water retention?

Iron deficiency anaemia can lead to water retention — otherwise known as fluid accumulation.

This presents itself as bloating and is particularly apparent in the stomach. It should be noted that water retention is not the same as belly fat, which is typically a consequence of weight gain from a surplus of calories. This positive calorie balance can result from overeating and under-exercising. 

To avoid water retention as a result of low iron, be sure to stay hydrated by drinking plenty of water and herbal teas. 

Common causes of iron deficiency

A range of factors can lead to low iron levels in the body, affecting anyone no matter the age.

Women who are of reproductive age and experience heavy periods or are breastfeeding are most at risk of developing iron deficiency anaemia. However, other common causes include: 

• Pregnancy: Pregnant women have a greater demand for increased blood volume and hemoglobin for the growing foetus which can lead to low iron levels. 
• Inability to absorb iron: Those with intestinal disorders like coeliac disease can experience an inability to absorb iron, which is absorbed into the bloodstream from food in the small intestine. If you’ve had part of your small intestine removed or bypassed surgically, you may also struggle to absorb iron. 
• Poor diet: Iron can be found naturally in a range of foods, but consuming too little can lead to iron deficiency. While meat is known to be a good source of iron, it’s also found in eggs, leafy green vegetables, and other foods (which we'll get to shortly). 
• Blood loss: Blood is made up of red blood cells that contain iron, so it’s natural to lose iron with blood loss. As mentioned before, women who are menstruating or have heavy periods will be at greater risk of iron deficiency anaemia. Slow, chronic blood loss within the body as a result of a peptic ulcer, a colon polyp, or colorectal cancer can also result in iron deficiency anaemia. 

Signs you have an iron deficiency

When the body struggles to produce hemoglobin and red blood cells, vital organs and tissues don’t get enough oxygen.

This decreased oxygen delivery to the entire body that results from iron deficiency is felt around the body. So, if you have iron deficiency anaemia, you’ll likely experience the following symptoms: 

• Low energy and unexplained feelings of tiredness, weakness, and fatigue 
• Concentration and memory issues
• Pale or yellow “sallow” skin 
• Shortness of breath or chest pain, particularly when engaged in physical activity 
• Rapid heartbeat  
• Restless leg syndrome 
• Cold hands and feet
• Unusual cravings for non-nutritive substances like ice, dirt, or starch
• Hair loss and brittle nails 
• Low thyroid function
• Gastrointestinal upset 
• Sore or smooth tongue 

The 3 stages of iron deficiency

While the body typically generates a steady flow of iron from nutrient-rich foods, iron deficiency can manifest in 3 stages.

Stage 1 

• The supply of iron to make new hemoglobin and red blood cells begins to deplete.
• Red blood cells aren't affected at this stage.

Stage 2

• Low iron stores begin to affect the production of red blood cells.
• Latent iron deficiency or iron-deficient erythropoiesis occurs, where the lack of iron limits the production of hemoglobin and other iron-requiring compounds.
• The bone marrow will make red blood cells without enough hemoglobin as a result of low iron stores. 

Stage 3 

• Lack of iron causes the concentration of hemoglobin to drop below the normal range.
• Symptoms of iron deficiency anaemia are experienced.

Can increasing your iron intake help with weight loss?

Increasing your iron intake can help with weight loss in 2 ways. Firstly, eating iron-rich foods that are nutrient-dense and part of a healthy, balanced diet can help assist you on your journey towards your weight goal.

As your iron levels increase, you’ll also find yourself having more energy. This change is a positive for your lifestyle, providing you with the energy you need for exercise and physical activity which are important factors for any weight loss journey. 

Plus, low iron has been seen to impact the thyroid hormone and slow metabolism [4].

By increasing your iron, you’ll improve these areas of your health, consequently boosting your body’s ability to burn calories. This is essential for anyone looking to lose weight, as you want to enter into a calorie deficit to achieve your weight loss goals. 

8 iron-rich foods to add to your plate

If you’re dealing with low iron levels, you may find yourself wondering if supplementation is the way to go.

Thankfully, as an essential nutrient for optimal health, you can get sufficient iron from your diet. Consider adding these 8 iron-rich foods to your diet:

1. Red meat

Red meat is rich in protein, zinc, several B vitamins, and iron and, according to studies, those who eat it are less likely to develop iron deficiency [5]. 100 grams of ground beef contains 2.7 mg of iron, with red meat being the most easily accessible source of heme iron.

Just be sure to stay within the recommended intake of 65g per day and to choose lean, unprocessed meats [8].

2. Spinach

Low in calories but high in nutrients, 100 grams of spinach contains 15% of the recommended daily intake. Spinach is also rich in vitamin C, which has been shown to improve iron absorption [6]. 

3. Legumes

Beans, lentils, chickpeas, and soybeans are all loaded with nutrients. They are also a great source of iron, particularly for those who are vegetarian or stick to a plant-based diet. One cup of cooked lentils contains 6.6 mg of iron. 

4. Turkey

Along with several vitamins and minerals, turkey provides 13% of the recommended daily intake of iron with 100 grams containing 1.4 mg. It’s a high-protein food that can aid weight loss by satiating hunger and increasing metabolism. 

5. Tuna

Fish has a host of valuable nutrients but is also high in iron. An 85-gram serving of canned tuna contains 1.4 mg of iron and omega-3 fatty acids, which have a range of health benefits. 

6. Pumpkin seeds

They may be small, but pumpkin seeds are a great source of iron. 28 grams contains 2.3 mg of iron, or 13% of the daily recommended intake. 

7. Liver and organ meats

Organ meats like liver, kidneys, brain, and heart are all very high in iron, with 100 grams containing 6.5 mg of iron. They are also high in essential nutrients like protein, B vitamins, and selenium. 

8. Dark chocolate

Chocolate with a minimum of 70% cocoa has a range of health benefits, with studies even showing it can be beneficial for cholesterol and reduce your risk of heart attack and stroke [7]. When it comes to iron, a 28-gram serving of dark chocolate contains 3.4 mg of iron. 

While these foods are rich in iron, it’s also important to consider the preparation and what can be done to enhance iron absorption.

Consuming foods rich in vitamin C helps you absorb more iron.

So, using lemon juice over meat, or eating kiwi fruit, berries, or capsicum uncooked at the same time as the foods listed above, can all help with iron absorption. Likewise, consuming calcium-rich foods like milk or cheese can reduce iron absorption, so it’s best to avoid them when eating a meal. 

Other ways to overcome iron deficiency anaemia

If you’re experiencing symptoms of iron deficiency anaemia, it’s important to consult your doctor or healthcare practitioner. As well as identifying the cause, they will be able to assist in developing a treatment plan, which may entail iron infusions, injections, iron supplements, or B12 supplements.

In severe cases, medications may also be prescribed to boost red blood cell production. 

Ultimately, if you’re struggling with weight gain or having difficulty reaching your weight loss goals as a result of iron deficiency anaemia, it’s important to focus on eating iron-rich foods that are packed with essential vitamins and minerals.

Of course, sustainable weight loss involves a holistic approach, which is why it’s worth considering Juniper’s Weight Reset Programme.

You can kickstart your weight loss journey with Wegovy or Mounjaro, two groundbreaking weight loss medications that mimic the GLP-1 and GIP hormone respectively to help control cravings, delay stomach emptying, and keep you feeling fuller for longer.

And both are incredibly effective: semaglutide (the active ingredient in Wegovy) can lead to a 15% average weight loss in 12 months, while tirzepatide (the active ingredient in Mounjaro) can lead to a 19.5% average body weight loss in 52 weeks.

On top of the medication, you’ll also receive hands-on support to make those lifestyle changes required to lose weight and gain access to certified clinicians who are here to help you every step of the way.

Whether you’re looking to break unhealthy habits that are holding you back from your weight loss goals, or simply want to take a holistic approach to your health, Juniper’s Weight Reset Programme can help you achieve your weight loss goals sooner, and see you stick to them for life.

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