Blog Weight Loss Weight Management Thyroid And Weight Gain: Why It Happens And What You Can Do About It

Thyroid And Weight Gain: Why It Happens And What You Can Do About It

Your thyroid gland is an important part of your endocrine system, the system of glands that regulates your hormones. Among other things, it helps control the rate at which your body uses energy, makes proteins, and manages the way your body uses carbohydrates and fats. It’s no wonder then that if something goes wrong with your thyroid gland, you might end up experiencing profound changes in your body. If you have an overactive thyroid – hyperthyroidism, your metabolism speeds up and you might lose weight without even trying (3). But if you have hypothyroidism, where your thyroid gland doesn’t make enough hormones, you might find it difficult to lose weight – despite eating well and exercising regularly (4). Let’s take a closer look at what happens to your body when you have problems with the thyroid gland and how this may lead to weight gain.


What Is Your Thyroid Gland?

As mentioned, your endocrine system includes a number of different glands that work together as a team, including your pituitary gland, hypothalamus, pineal gland, parathyroids, thymus gland, adrenal glands and pancreas.

Your thyroid is particularly important because it plays a role in controlling your metabolism – the way your body digests food and turns it into energy (10).

You have two main lobes to your thyroid gland, one on the right side of your neck and another on the left side of your neck. Hormones released by your thyroid travel through your blood and help regulate the metabolic activity of nearly every cell in your body, from the way you burn calories to how fast or slow your heart beats (10).

What Is Hyperthyroidism? 

When you have too much thyroid hormone in your body, it’s known as hyperthyroidism. This might be caused by:

An Overactive Thyroid Gland

Hyperthyroidism is usually caused by a problem with the gland itself. This includes abnormal function of the pituitary gland that causes your thyroid to produce too much hormone (3).

Illnesses Such As Graves’ Disease Or Toxic Multinodular Goiter

In Graves’ disease, a type of hyperthyroidism, antibodies cause your thyroid to produce extra hormones. In another type of hyperthyroidism known as toxic multinodular goiter, many nodules in your thyroid gland each have the potential to make their own excess hormone (3).

See also
Hormonal Belly Men: Causes And How To Fix It

Read More: Thyroid Diet Plan For Weight Loss: Foods To Eat, Foods To Avoid, And A Sample Meal Plan

thyroid and weight gain

What Happens When You Have Hyperthyroidism?

One of the most common symptoms of hyperthyroidism is unintended weight loss, despite a healthy diet and exercise routine – because you’re burning off so many calories at a more rapid rate. Other symptoms include (3):

  • An irregular heartbeat 
  • Rapid pulse, which can feel like your heart is racing 
  • A bulging neck
  • An increased appetite 
  • Difficulty sleeping 
  • Excessive sweating 
  • Mood swings 
  • Unintended weight loss despite a healthy diet and exercise routine

If hyperthyroidism isn’t treated, there’s a chance you’ll develop more severe problems with the function of your heart and bones.

What Is The Relationship Between Hyperthyroidism And Weight?

When you have an overactive thyroid gland, it sends your metabolism into overdrive. You might lose weight without even trying because several aspects of your metabolism are sped up (3):

  • You may find it difficult to eat enough calories to maintain your weight. 
  • Your heart rate speeds up, which burns extra energy. 
  • You might have trouble sleeping through the night, so your body doesn’t get a chance to complete the repairs it needs to properly function.
  • Your resting metabolic rate – the number of calories you burn to maintain your body’s functions while at rest – increases, burning more calories throughout the day.

Meal Plan

What Causes Hypothyroidism?

Hypothyroidism – or underactive thyroid – occurs when your thyroid gland doesn’t produce enough of the hormones that help regulate metabolism (4). It can be caused by:

An Underactive Thyroid Gland

Your thyroid might not be able to make enough hormones because of damage from either radiation or a disease, such as Hashimoto’s disease. Sometimes certain medications can contribute to hypothyroidism, such as lithium and amiodarone (Cordarone) (4).

Too Little Iodine In Your Diet

Your thyroid needs iodine to make hormones. If you don’t have enough in your diet, you might develop hypothyroidism (4).

Congenital Hypothyroidism

Congenital hypothyroidism occurs while you’re still in the womb, before your thyroid has had a chance to start working. This can happen for several reasons, including if your mother took certain medications during pregnancy or had an illness that affected her thyroid (4).

See also
Does Progesterone Make You Hungry? How To Deal With Hormonal Cravings

thyroid and weight gain  

What Happens When You Have Hypothyroidism?

Hypothyroidism causes your metabolism to slow down, so it can be harder for you to burn calories, resulting in weight gain over time. Other symptoms of hypothyroidism include (4):

  • Fatigue 
  • Depression or feelings of sadness 
  • Constipation 
  • Dry skin and hair loss, which may result in coarse hair texture and dry, brittle nails.

Other symptoms can also occur depending on the severity of your condition. If you have too little thyroid hormone, it can affect other organs and cause problems such as (4):

  • Muscle weakness, joint pain or stiffness 
  • Increased sensitivity to cold temperatures 
  • Slowed heart rate that could progress into a dangerous rhythm called atrial fibrillation 
  • Depression or feelings of sadness 
  • A small goiter in your neck. A large goiter can also cause discomfort, such as with swallowing or breathing 

If you go untreated for an extended period of time, hypothyroidism can affect your memory and ability to concentrate.

Whether you’re looking to simply pep up your fitness routine, jazz up your diet with mouth-watering low-calorie recipes or want to get your act together and significantly drop that number on your scale – BetterMe app has got you covered! Improve your body and revamp your life with us!

thyroid and weight gain

What Is The Relationship Between Hypothyroidism And Weight Gain?

People who have an underactive thyroid tend to gain weight more easily than the average person, particularly around their waistline. This might happen because your metabolism is slowing down so you don’t burn as many calories each day (4).

When combined with a poor diet and lack of physical activity, you might find it difficult to lose weight even if you try. If you have hypothyroidism, you can gain up to 5 pounds (2.3 kilograms) every year after the age of 30 (4).

Can You Reverse The Damage?

The good news is that most types of hypothyroidism are easily treated to prevent further health problems from developing, including those related to weight gain. With proper treatment, you should be able to restore your metabolism to normal and maintain a health weight.

See also
Fat Storage In Body: Everything You Need To Know To Lose Weight

If you suspect that your sudden weight gain could be due to a thyroid problem, make an appointment with your doctor for a checkup. Don’t let concerns about your weight keep you from speaking up about your health concerns.

How To Overcome Hypothyroidism And Lose Weight

Losing weight while battling  an underactive thyroid can seem overwhelming. Here are some steps you can take to get started:

Try A Thyroid-Friendly Diet

A diet rich in proteins, fruits, vegetables, and moderate carbohydrates may be effective in helping people with hypothyroidism lose weight. While there aren’t many restrictions on this diet, you may need to stay away from goitrogenic foods such as cruciferous vegetables that can disrupt your thyroid function. Talk to your doctor to find out if this is necessary for you.

Here are some diet tips that may help:

Consider A Calorie Deficit

Weight loss requires that you expend more calories than you eat. If you’re not currently burning as many calories as you consume, then try cutting back on your food intake and/or increasing the amount of exercise you do each day.

Be careful with fad diets. They may have a short-term effect on your weight, but there’s a good chance they won’t help you maintain your results in the long run (5).

thyroid and weight gain

Eat More Lean Protein

Eating a diet rich in lean proteins can help you maintain muscle mass and reduce your appetite. Furthermore, most protein sources contain iron, zinc and selenium-essential nutrients that people with hypothyroidism should get sufficient amounts of (9). Seafood in particular can also help you make sure you get enough iodine. Try adding more of these healthy protein options to your diet:

  • Eggs
  • Chicken, turkey and other poultry
  • Fish like salmon, mackerel and tuna 
  • Canned tuna
  • Lean beef or pork
  • Beans and legumes

Eat More Fiber From Whole Grains

Fiber is an important part of any healthy eating plan. It slows down digestion so you feel full longer, which can help when trying to lose weight (8). You can get fiber from whole grains like:

  • Oatmeal and oat bran
  • Whole wheat and brown rice 
  • Quinoa 
  • Whole-grain pasta
See also
Subcutaneous Fat Vs Visceral Fat: Which Is Worse?

Supplement Your Diet With Healthy Oils

While you may not think of oil as part of your daily diet, there are several healthy oils that have unique benefits. They can help you lose weight and stave off weight gain (1). Here are some great heart-healthy ways to get the fat you need without overdoing it on calories:

  • Avocado oil, Olive oil, Flaxseed oil 
  • Nuts like almonds, pecans and walnuts and nut butters
  • Seeds like sunflower and pumpkin seeds

Read More: Meal Replacement Diet: What It Is And How It Works


Eat More Fruits And Vegetables

Fruits and vegetables are a great source of vitamins, minerals, fiber, antioxidants, and phytochemicals that your body needs to function at its best (2). The following fruits and veggies contain higher levels of soluble fiber:

  • Citrus fruit like oranges, grapefruit and tangerines
  • Apples 
  • Pears
  • Strawberries 
  • Leafy greens like broccoli, spinach and kale 
  • French beans
  • Chickpeas, kidney beans and white beans
  • Artichoke 

Try Intermittent Fasting If Your Thyroid Symptoms Are Under Control

Intermittent fasting is another effective way to lose weight. This dieting method involves alternating between periods of eating normally and going without food for a specific number of hours or days. You can use this method in several different ways

  • 16/8 Method: Fast for 16 hours and eat during an 8-hour window (other variations include 14/10, 12/12, 20/4)
  • Alternate Day Fasting: Alternate between fasting (low calorie intake) days and normal eating days

If you have thyroid disease, talk to your doctor first before attempting any type of intermittent fasting. It may be safe for some people, while others may experience adverse effects

thyroid and weight gain

Get Active To Shed Those Extra Pounds

Inactivity can slow down your metabolism and cause health problems that lead to weight gain.

Losing weight often requires being more active. Try upping your daily activity by walking a little bit longer or avoiding elevators and escalators in favor of the stairs at work or home. If you’re physically able, try engaging in more strenuous cardiovascular exercises like running, swimming, or biking.

See also
Why Am I Losing Weight on the Face? Exploring the Causes and Solutions

You may also want to try strength training with weights or resistance bands. Strength training is the best way to tone your muscles and improve your bone health (6). With consistent strength training, you can reduce the amount of fat stored around your abdomen, hips, and waistline-regions where people tend to hold weight more than on other parts of their bodies.

Consult A Doctor

If you’re having a difficult time losing weight, then don’t hesitate to get in touch with your doctor. They can help you determine if an underlying thyroid disease is responsible for the excess fat on your body. If so, they may recommend one of these diagnostic tests:

  • TSH test 
  • Free T4 test 
  • Free T3 test 
  • Thyroid ultrasound

They can also help you decide how to treat your condition, which may include prescribing medication or dietary changes.

If you struggle to even flirt with the idea of giving up your favorite foods or working out till your legs give way – BetterMe app is here to breathe a fresh perspective into the way you view the weight loss process! Check out the app and experience the fun side of fitness and dieting with BetterMe!


Improve Your Sleep

Sleep affects hormonal balance, mental health, and metabolism (7). That means you can affect weight gain through your sleep habits. To improve your sleep:

  • Avoid taking naps 
  • Go to bed early enough to get at least 8 hours of quality sleep each night
  • Limit alcohol and caffeine intake before bedtime
  • Try winding down with some light reading before bed 
  • Create a quiet, relaxing sleep environment. Turn off the TV and use your phone as little as possible while you’re in bed 

The Bottom Line

The thyroid gland is responsible for producing essential hormones that determine the rate at which your body burns energy. When this gland malfunctions, it can cause weight gain or weight loss.

The good news is that you can manage your thyroid symptoms with dietary changes and lifestyle adjustments. However, if you’re having trouble losing weight despite making these lifestyle modifications, then ask your doctor about diagnosis and treatment options.



This article is intended for general informational purposes only and does not address individual circumstances. It is not a substitute for professional advice or help and should not be relied on to make decisions of any kind. Any action you take upon the information presented in this article is strictly at your own risk and responsibility!


  1. A healthy approach to dietary fats: understanding the science and taking action to reduce consumer confusion (2017,
  2. Health Benefits of Fruits and Vegetables (2012,
  3. Hyperthyroidism (2016,
  4. Hypothyroidism (2017,
  5. Potential long-term consequences of fad diets on health, cancer, and longevity: lessons learned from model organism studies (2007,
  6. Strength training builds more than muscles (2021,
  7. The Extraordinary Importance of Sleep (2018,
  8. The Health Benefits of Dietary Fiber (2020,
  9. The History and Future of Treatment of Hypothyroidism (2016,
  10. Thyroid Hormone Regulation of Metabolism (2014,