WEIGHT MANAGEMENT ∙ 5 minutes read

9 common reasons why you’re not losing weight when you diet and exercise

By Kirsty Mason | Medically reviewed by Dr Luke Pratsides

If you’ve been following a healthy routine - frequent gym sessions and a diet fit for a rabbit - then there’s nothing more frustrating than seeing lacklustre results when it comes to weight loss. 

Losing weight is no easy journey, especially if you’re targeting stubborn belly fat. Although it’s frustrating when the weighing scales won’t budge, it’s crucial not to throw in the (exercise) towel. There are plenty of reasons why you’re not seeing the weight loss results that you initially expected. We take a look at the most common challenges that negate results from a good weight loss regime and what the solutions are.

1. Your weight is plateauing

When you first start a healthy routine, it’s common to see an initial period of rapid weight loss, followed by a period where the scales have become stagnant, despite sticking to the same routine. There are several reasons why this may occur. 

Firstly, when you initially cut down on calories, your body will begin to use stores of glycogen. It’s a rapidly available source of energy for the body and is stored in the liver, muscle, and fat cells. One of the components of glycogen is water and when the body experiences a calorie deficit, it will seek energy from this molecule. This, in turn, will lead to the release of water and explains why weight loss initially occurs rapidly (as you’re losing water weight) before plateauing when the glycogen stores adapt. Once the water has depleted, your body needs to work extremely hard to lose the much more stubborn fat cells. To target fat cells, you may need to increase your calorie deficit.

Another reason why your weight loss may have plateaued is that your general fitness has increased. After losing weight, your body will burn fewer calories for the same movements because there’s less weight to carry and your fitness has increased. This means that you’re expending less energy than you were when you carried more weight. 

Lastly, weight plateauing can occur because of the adaptive behaviour of the body. You have what’s called ‘muscle memory’ where your muscles adapt to a particular exercise and learn how to do the same exercise while using less energy. This is why it’s so important to mix up your fitness routine, working as many different muscle groups as possible and doing different types of resistance exercises.

2. You’re gaining muscle and losing fat

Seeing the weighing scales tick up might make you panic at first, but if you’ve been following a good fitness regime and pumping up the biceps, then this could explain the extra weight. This is because muscle is denser than fat, meaning it takes up less space, so you can have more of it (and therefore weigh more) despite retaining a similar figure. Many gyms have a machine that can measure the ratio of body fat to muscle, which will help you to understand if weight gain is down to an increase in muscle mass.

3. You’re calculating the calorie deficit inaccurately 

People tend to overestimate how many calories they’ve burned in a workout session and underestimate how many calories they’ve consumed. A 6-month controlled trial found that understanding of the relationship between calorie deficit and desired weight loss was poor among obese patients.

To put it into perspective, to burn 500 calories, you probably need to cycle for over an hour (depending on various factors such as your weight and gender). When it comes to consuming 500 calories, the effort is significantly reduced. Just one single sugar-frosted doughnut could easily pack in 500 calories in just a few minutes. That’s why people tend to see poor results when they focus purely on exercise and don’t adjust their diet. To lose and maintain healthy weight loss, you should combine both diet and exercise.

4. You’re eating ‘healthy’ foods that aren’t actually healthy

The weight loss industry is riddled with foods purporting misleading messages about the weight loss benefits of a particular product. Some ‘healthy’ foods can even lead to weight gain. 

Products labelled ‘low-fat’ often have added sugar to counteract the loss of flavour so it’s important to check the sugar content before opting for the lower fat product. Breakfast bars, cereals and yoghurts can also be loaded with sugar, despite a reputation for good health. Frozen yoghurt, often labelled as a healthy alternative to ice cream, is actually packed with sugar and should be avoided if you’re on a strict diet.

It’s easy to be misled by the types of bread that seem healthy on the surface. If it’s labelled ‘multigrain’ or ‘multiseed’, then the bread can be either brown or white (the labelling refers to the fact it contains multiple grains or seeds, rather than whether or not it’s been made with whole grains). White bread is highly processed, metabolised quickly in the body to sugar, and contains additives whereas bread that’s made with whole grains (such as whole wheat) contains a high amount of fibre, which will make you feel fuller for longer and slow down the conversion of carbohydrate to sugar in the digestion process.

A healthy diet should be balanced, with a high amount of protein and fibre to satisfy your appetite. Although protein is essential, be wary of protein bars as they can contain an incredibly high amount of sugar. Try our 7-day high cholesterol diet plan or prediabetes diet plan to kickstart a healthy and nutritional diet.

5. You’re not getting enough sleep

A meta-analysis of sleep duration and obesity found that lack of sleep was associated with an increased risk of obesity in both children and adults.

Sleep is critical for all sorts of reasons - it consolidates our memory, regulates our mood, aids physical recovery and works as a crucial part of the restoration process of the mind and body. A study into the reasons why sleep deprivation is linked to weight gain found that energy expenditure increased after a restless night’s sleep, meaning the body needed more energy (i.e. food) than it would after a good night’s sleep. They found that participants would then overeat in response to their increased cravings for food, leading to weight gain.

6. You’re not drinking enough water

If you’ve heard that drinking more water can help with weight loss, you probably thought it was too good to be true. In fact, there are multiple scientific studies to back this claim.

A study on the effects of drinking water before a meal found that drinking 500ml of water prior to a meal led to a reduction in food intake. 

The reason why water consumption could aid weight loss is still up for debate but it may be because it promotes feelings of fullness or increases energy expenditure in the body, therefore, burning more calories.

7. You’re drinking too much alcohol

There’s a reason it’s called a beer belly. Excessive drinking when you’re on a diet is a big no-no. That’s because alcohol contains what’s known as ‘empty calories’. Alcoholic beverages contain empty calories because they tend to be high in calories but offer no nutritional value.

In the absence of protein or fibre, you’re less likely to feel full after a drink. And alcoholic beverages don’t just pack in the calories, with many cocktails, mixers, beers, and wines bursting with added sugar. High sugar content influences appetite control and there’s some evidence in mice to suggest that alcohol activates the brain’s starvation signals.

8. You’ve got a medical condition or you’re taking certain medication

Sometimes, a medical condition can make you vulnerable to weight gain. Hypothyroidism is a condition where the thyroid gland (a butterfly-shaped gland located in the neck) is underactive and, therefore, doesn’t produce enough hormones. These hormones regulate metabolism, meaning that your body is naturally burning fewer calories than it would if you had a normal functioning thyroid. In response to this dysfunction, the body will accumulate excess salt and water, leading to weight gain.

Diabetes is another condition that has ties to weight gain. Type 2 diabetes is characterised by excessive sugar (glucose) levels in the blood brought on by a resistance to insulin. Insulin is critical for the transportation of glucose and an imbalance of the substance promotes fat storage. The condition can be managed with medication and healthy lifestyle choices. You can reverse your risk of developing the condition by following a prediabetes meal plan. The best way to check your risk of health conditions such as hypothyroidism and diabetes is to take a blood test.

Weight gain could also be a side effect of certain medications, including some anti-depressants or medication for a migraine. You should never cease medication without consulting your doctor first.

9. You’re stressed

Stress has a profound effect on the body and can manifest itself in all sorts of ways. Stress raises levels of cortisol, which is linked to weight gain. A 6-month naturalistic study found that chronic stress and higher levels of cortisol were predictive of weight gain.

A study on the effect that stress has on metabolic rate found that those who reported a higher number of stressors burned fewer calories at rest (resting energy expenditure) compared to those who reported fewer stressors. Investigations found they also had higher levels of both cortisol and insulin. Raised levels of insulin can lead to weight gain as the hormone regulates the absorption of sugar which the body will convert to fat when overloaded in the bloodstream.

The bottom line

It’s incredibly frustrating when you follow a healthy diet and routine yet the scales won’t seem to budge. But it’s crucial not to give up as there are several reasons why you might not be seeing the results you expected - and there could be an easy solution. 

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