7 Reasons Why You Can’t Lose Weight No Matter What

“Why can’t I lose weight no matter what I do?” So many people have asked themselves that question. If it sounds familiar, rest assured you are not alone. Weight loss is a big issue for many. No matter how much you go on a diet or how many exercise programs you follow, it seems that the numbers just don’t go down.

Indeed, it is demoralizing and frustrating when you can’t seem to shed a pound, even though you are doing all the right things. Read on to understand why you might be struggling to lose weight despite your best efforts.

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1. You may have a medical condition that causes weight gain

If you have a medical condition causing weight gain, you may struggle to lose weight no matter how much you exercise or how well you follow any diet.

The following medical conditions commonly cause weight gain.

Hypothyroidism (an underactive thyroid)

Your thyroid plays a large part in regulating your metabolism. When your thyroid isn’t functioning properly, your metabolism slows down, leading to weight gain¹. According to research, up to 3.7% of Americans have an underactive thyroid².

Polycystic ovarian syndrome (PCOS)

Approximately 4% to 20% of women of reproductive age worldwide suffer from PCOS³. It is associated with hormonal dysregulation and insulin resistance. Insulin resistance causes raised blood insulin levels, which leads to weight gain.

If you struggle with PCOS, you may find it difficult to lose weight, no matter how hard you try⁴.


One of the physical symptoms of depression can be increased appetite (hyperphagia), which can lead to weight gain. 

Depression may also contribute to weight gain through its association with poor eating habits, physical inactivity, and poor adherence to recommended lifestyle modifications⁵. You may struggle to lose weight if you are clinically depressed.


Research has shown that disrupted or poor quality sleep can lead to obesity⁶. If you skip a night of sleep every now and then, it’s unlikely to have a huge effect on your waistline. However, if you are chronically sleep-deprived, it may be the reason you’re struggling to lose weight. 

2. Medication may be stopping you from losing weight

Various medications can cause weight gain. Check the following list to see whether the meds you’re taking are causing you to retain extra pounds⁷.

  • Some antidepressants, including selective serotonin reuptake inhibitors (SSRI), monoamine oxidase inhibitors (MAOIs), and amitriptyline

  • Some types of antipsychotics

  • Insulin and sulfonylureas, commonly used in the treatment of diabetes

  • Certain antiepileptic medication

  • Cortisone

  • Contraceptives

  • Some hypertension medications such as beta-blockers

3. Age

Various physiological changes happen to your body as you age. Some of these are due to hormones.

In women, menopause has been linked to weight gain and difficulty losing weight⁸. In men, their testosterone levels drop when they age, leading to decreased lean muscle mass. Muscle is a metabolically active tissue, and the decrease in lean muscle mass causes a drop in resting metabolic rate and subsequent difficulty in losing weight⁹.

Approximately 3 to 8% of muscle mass is lost per decade after the age of 30. Beyond 60, this rate is even higher. 

4. You may have been dieting too much

It sounds counterintuitive that dieting can lead to a state where you can’t lose weight, but the reality is that it can. This is especially true when you engage in yo-yo dieting, a cyclic pattern of losing weight and then regaining it¹⁰.

Research has shown that cycling between states of calorie deprivation, such as being on a strict diet, and normal eating can lead to fat accumulation. A very simplified explanation of why this happens is that your body anticipates that it will hit a period of starvation in the future, so it accumulates fat reserves for when this happens¹¹.

Yo-yo dieting has also been shown in preclinical studies to cause changes in the immune cells in fat tissue, making them more resistant to weight loss efforts¹². Further discussion of this has suggested that activation of certain parts of the immune system in fat tissue by cyclical weight loss and gain plays a role in the development of obesity.

However, more research is needed to confirm these findings and evaluate the extent to which this is the case¹³.

5. Your scale may not be telling you the whole story

If you are following a diet and exercising simultaneously, you may be losing fat at the same time that you are building muscle. Your scale won’t be able to differentiate between the fat you’ve lost and the muscle you’ve gained, so your weight may be the same, but your body composition could be totally different.

A pound of muscle is denser than a pound of fat, so a more muscular version of yourself will look different from a fatter version of yourself, despite your weight being the same. If you think that this is the case, it may well be worth monitoring your weight loss progress by measuring your body fat percentage instead of your weight.

6. Genetics

Certain factors that could contribute to your difficulty losing weight are beyond your control. Research has shown that there is a strong genetic component to obesity. Twin studies have shown that between 60% to 90% of your predisposition to obesity could be genetic¹⁴. If you are struggling to lose weight, it may be because of your genes.

There is another way that genetics can influence your weight. Excess maternal gestational weight has been linked to obesity in offspring¹⁵. So, if your mother was carrying excess weight when she was pregnant with you may find you struggle to lose weight.

7. You may have unrealistic expectations

If you are struggling to get to your “ideal” weight, it might be time to reassess what you are basing your ideal weight on. Ask yourself whether you are trying to lose weight to be a stronger, healthier version of yourself or whether you are trying to lose weight to look a certain way.

If you have unrealistic expectations for your weight loss goal, it’s unlikely that you will ever be successful in reaching it.

The lowdown

Being unable to lose weight despite doing everything right is understandably frustrating. Knowing why you might not be losing weight can help you find your way back on track on your weight loss journey.

The next time you find yourself asking, “Why can’t I lose weight no matter what I do?”, schedule a consultation with your doctor. Together, you can find out whether you may have a medical condition that is hampering your weight loss progress or whether the medication you are taking is causing weight gain.

Once you’ve got the all-clear from your doctor, you can look at the other reasons you may not be losing weight and tackle them.

Remember, it is more important to be healthy than look a certain way. Instead of focusing entirely on the numbers on the scale, turn your focus to becoming a healthier and better version of yourself.

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