Second Nature logo



Why am I not losing weight?

Robbie Puddick
Written by

Robbie Puddick

Medically reviewed by

Fiona Moncrieff

11 min read
Last updated June 2024

Jump to: You’re not in a calorie deficit | You’re not eating enough | You’re relying on exercise alone | Take home message

Here are three main reasons you’re not losing weight:

1) You’re not in a calorie deficit

We have to be in a calorie deficit to lose weight, and it’s possible that despite your best efforts to be in one, you might be at an ‘energy balance’ where you’re consuming the same amount of calories that your body’s burning each day.

This is one of the reasons we don’t recommend calorie counting; it can be very difficult to measure how much you’re eating and burning accurately.

2) You’re not eating enough

When we go on a strict diet and restrict our calorie intake by too much, our brain responds by slowing down other processes in the body that require energy to preserve fat stores.

This starvation response is called metabolic adaptation, a safety mechanism by your body to encourage weight gain. It’s this response that causes weight loss plateaus, and it can also lead to a loss of muscle mass.

To lose weight sustainably in the long term, you need to eat more.

3) You’re relying on exercise alone

When going through a weight loss journey, people often think that by exercising more, they’ll burn off excess fat and be able to lose weight.

However, there are a few functions in the body working against you. Firstly, when we first start exercising, it can make us feel hungrier as the body tries to recover the energy lost to exercise.

Secondly, we often overestimate how much energy we’re burning through exercise and overcompensate in the meals after because ‘we’ve earned it’.

This is another example of why calorie counting is an unreliable tool for weight loss, and tuning into our body’s signals can support more weight loss.

Check my eligibility

Weight loss is challenging

As you have gathered from our list above, weight loss can be hard work. You’ve often got your body and brain working against you to try and recover the energy you’re trying to burn off to lose weight.

Alongside this, the advice you’ve received to help you lose weight is likely unscientific and unsustainable.

You may have been informed that you simply need to ‘eat less and move more’, and you’ll lose weight.

This oversimplifies how the body works and often leads to misguided advice that promotes severe restriction and unsustainable exercise routines.

The truth is that weight loss doesn’t need to be this way. You don’t need to count calories; you don’t need to restrict yourself, you don’t need to exercise hours each day, and you don’t need to be on ‘the wagon’.

A more sustainable alternative

At Second Nature, we provide a different approach to weight management that can curb your cravings, manage your blood sugar levels, and help boost fat loss.

An approach that doesn’t make you count calories, weigh macros, go on strict fad diets and cut out whole food groups, and one that goes at your pace with the support of a registered dietitian or nutritionist.

The NHS trusts our approach in the UK to manage obesity and type 2 diabetes. It has been proven to be more effective than our competitors in a recent paper in the British Medical Journal.

The results showed that Second Nature was more than twice as effective at supporting weight loss for individuals participating in the NHS Diabetes Prevention Program after 12 months.

If you’re sick of the yo-yo dieting cycle, of always wondering why you’re not hitting your weight loss goals despite doing everything you’re being told to do, and you’d like to join 150,000 others who’ve found losing weight feel second nature, click here to take our health quiz.

Otherwise, keep reading as we dig into the science of why you’re not losing weight and what you need to do instead to lose body fat and reach a healthy weight.

1) You’re not in a caloric deficit

The basic science of weight loss is simple. You need to burn more calories than you consume, and you’ll lose weight.

This understanding leads to the advice that we simply need to count the number of calories we’re eating, subtract it off and we’ll be in a caloric deficit and lose weight.

Unfortunately, humans are very poor estimators of the energy density of foods. Research has shown that we can underestimate the calorie content of foods by up to 16%.

Other studies evaluating the effectiveness of food diaries have also shown that people may omit up to 9% of the food they consume.

These studies suggest that we’re not only poor estimators of the calorie content of foods. As humans, we’re also prone to error and are likely to miss our snacks or fundamental elements of our meals.

While you might be doing your best to track what you’re eating to ensure you’re in a calorie deficit, you’re likely underestimating how much you’re eating.

You may also be omitting entire snacks or elements of your meals that contribute to your total energy intake.

Inaccuracies aside, there are other issues with calorie counting that might mislead you when you’re tracking calories.

Too much focus on calories

By focusing too much on the calorie content of foods, you might not be consuming higher-calorie foods that are more nutritious, like dairy, nuts, or avocados, thus leading to a feeling of hunger and an increased desire to eat.

By focusing on consuming only ‘low-calorie foods’, you’re likely restricting yourself too much, not giving your body enough of what it needs, and then you overcompensate by eating more. For many, this comes from snacks in between their low-calorie meals.

Interestingly, a recent study showed that restricting dietary fat to less than 30% of total energy during weight loss changed dopamine signalling in the brain.

This change in dopamine signalling encouraged the consumption of ultra-processed foods rich in refined carbohydrates, added fat, and sugar.

By focusing on the quality of the foods you’re consuming and not restricting high-calorie, high-fat foods like dairy, nuts, and avocado – you might find it a little easier to achieve a calorie deficit without feeling hungry.

This approach is why lower-carb diets have become more prevalent in recent years. Research shows they help people achieve a higher level of food satisfaction and fullness without consuming too many calories, and they lose weight.

Key points:

  • Humans are poor estimators of energy intake and are prone to errors when tracking calories.
  • Too much focus on calories leads people to consume nutrient-poor, low-calorie foods that leave them hungry.
  • You may need to eat more high-calorie foods that contain more fat to help you lose weight.

2) You’re not eating enough

Calorie counting and strict diets often encourage a crash diet approach of losing a lot of weight quickly and then attempting to maintain higher levels of weight loss in the long term.

It’s believed that this approach encourages people to ‘buy in’ to their diet and helps them continue making positive changes as they become motivated by their early success.

While this may work for some people, many of us will struggle with the strict rules and restrictions that these regimes will place on us, and the lack of enjoyment and satisfaction from food will result in a rebound effect where we overeat and regain the weight lost.

A randomised pilot study was conducted on overweight adults to determine the impact of a low-level calorie restriction (10% calorie deficit) to a moderate level (30% calorie deficit) on weight loss, hunger, and food satisfaction.

The results showed that the moderate calorie restriction group lost more weight after six months but then started to regain weight on average. In contrast, the low-level calorie restriction group lost weight more gradually and maintained their weight loss.

After 12 months, there was no difference in weight loss, with both groups losing around 9% of their body weight.

Interestingly, the moderate calorie restriction group also reported more hunger, more desire to eat foods outside of the study recommendations, and lower satisfaction with the foods offered during the study.

This is consistent with the science behind metabolic adaptation and the brain’s starvation response to caloric restriction. The more you try to restrict your intake, the more your brain will send signals to the body encouraging you to eat more.

This research suggests that over the long term, you’re more likely to lose weight and avoid weight regain by not being so restrictive in your approach.

Don’t fear fat

Fat is often avoided when people are counting calories or on strict diets because it contains more calories per gram than carbohydrates.

However, research has shown that consuming more fat and fewer carbohydrates can support weight loss and help you burn fat.

This was demonstrated by a study comparing a low-fat, low-carbohydrate, and Mediterranean diet (which is naturally higher in fat from olive oil, pork, and fish) and found that after two years, people following a low-fat diet lost an average of 3.3kg.

Comparatively, those following a Mediterranean diet lost 4.6kg and low-carbohydrate 5.5kg.

Interestingly, the individuals on the lower-carbohydrate diet were instructed to eat until they were comfortably full. In contrast, the individuals on the low-fat diet were required to consume no more than 1600 kcal per day.

Despite this, the low-carbohydrate group consumed fewer calories than the low-fat diet and eventually lost more weight. This suggests that diets higher in fat can be ‘self-limiting’ and help people lose weight without counting calories.

Key points:

  • Calorie counting and fad diets often promote dramatic cuts in energy intake, leading to significant weight loss in the short term.
  • However, research has shown that less restrictive diets can support as much weight loss in the long term without the adverse effects of feeling hungry and deprived.
  • Research has shown that consuming more fat as part of your weight loss approach can help you eat fewer calories without feeling hungry and deprived.

3) You’re relying on exercise alone

People often assume that exercise is all you need to do to lose weight. The pounds should drop by burning extra calories and continuing to eat the way you are.

Unfortunately, what tends to happen is that individuals compensate for most of the energy they’ve burned through exercise – and you’ll experience little to no weight loss.

A recent study compared the impact of exercise for two or six days a week on overweight participants’ energy intake, hunger hormones, and weight loss.

The study showed that weight loss between the two groups was very modest, with the six-days-a-week group losing 1.04kg and the two-days-a-week group losing 0.76kg.

Interestingly, despite differences in exercise intensity, time, and changes in the hunger hormone ghrelin – both groups compensated equally in line with their exercise levels. So, the participants that exercised more simply ate a bit more to compensate for this.

This is consistent with multiple lines of evidence suggesting that exercise is often not enough to promote significant weight loss in the long term.

Focus on what you’re eating, too

While exercise alone doesn’t seem to support significant weight loss, diet and exercise interventions are effective at supporting weight loss, which seems to be primarily driven by the change in eating habits.

A randomised controlled trial compared the impact of exercise alone, diet, or exercise and diet together on weight loss after 12 months in overweight participants.

The results showed that both the diet and diet and exercise groups lost a significant amount of weight (10% and 9%), while no weight loss was observed in the exercise group.

This study also analysed a measure of cardiovascular fitness, which we call peak oxygen consumption. Interestingly, the diet and exercise group showed a more significant improvement than exercise alone (17% vs 8%).

Peak oxygen consumption is not only a measure of fitness but also of your health. Research has shown that the higher your peak oxygen consumption, the lower your risk of all-cause and cardiovascular mortality.

Exercise is about more than calories

Exercise is often viewed through the lens of how many calories it burns. But this overshadows exercise’s overall impact on our quality of life.

Exercise has been shown to lower your risk of all the major chronic diseases such as heart disease, type 2 diabetes, and cancer. It’s also been shown to help lower stress and improve mental health.

Additionally, research has shown that individuals who successfully lose weight and keep it off tend to be more physically active than those who regain the weight they lose.

So, exercise – cardio, strength training, or any form of physical activity like walking the dog or gardening – can be an excellent way to improve your health, reduce your risk of chronic disease, and increase your chances of maintaining weight loss in the long term.

But how do I combat overcompensating from exercise?

In the long term, exercise has been shown to reduce feelings of hunger and increase feelings of fullness (satiety). Exercise improves satiety signalling in your brain, allowing you to eat less overall.

However, in the short term, or when you’re new to exercise, you might initially feel more hungry as your body adapts.

Here are five ways to help you avoid exercise-induced hunger during a weight loss journey:

  1. Eat enough healthy food in your main meals: As we’ve highlighted in this article, eating until you’re comfortably full in each meal will provide your body with everything it needs.
  2. Stay hydrated and drink enough water: Your body can make you feel hungry when you’re not hydrated. If you keep on top of your water intake, this will help to keep hunger at bay.
  3. Eat enough protein: Protein promotes greater feelings of fullness compared to carbohydrates, be sure to consume at least 30-40g of protein in each meal.
  4. Eat healthy snacks: Enjoy protein and fibre-rich snacks like peanut butter and apple if you’re feeling hungry between meals.
  5. Time your workouts to finish in line with your meals: If you plan a workout to finish just before your main meals, you’re less likely to snack and overcompensate. So, you can workout, have breakfast, or workout just before lunch. Whatever works for you.

Key points:

  • Exercise as a sole intervention has not been shown to promote weight loss.
  • However, exercise combined with improved eating habits promotes weight loss and may support more successful maintenance of weight loss.
  • Exercise is more than how many calories it burns; it promotes significant health benefits independent of weight loss.
  • Exercise can support satiety in the long term, helping you eat less.
  • However, it can promote hunger in the short term. You can avoid this exercise-induced hunger by eating enough in your meals, staying hydrated, eating enough protein, eating healthy snacks, and timing your workouts well.

Take home message

The main reasons you’re not losing weight are likely down to the poor advice you’ve been trying to follow to help you achieve the weight loss you’re after.

The diet culture has continued to promote the notion that weight loss is all about the numbers. All you need to do is count your calories, and you’ll lose weight.

The truth is much more complicated than that. Our body is specifically designed to fight against severe energy restriction to protect us from harm and increase our chances of survival.

You can achieve sustainable weight loss. But it starts with ignoring much of what you’ve previously been told you need to do to lose weight.

If you’d like to experience a weight loss plan that isn’t restrictive and will leave you feeling full, satisfied, and full of energy, click here to try our 7-day NHS-trusted meal plan.

Meal Plan

Download our free, indulgent 7-day meal plan

It includes expert advice from our team of registered dietitians to make losing weight feel easier. Subscribe to our newsletter to get access today.

I've read and agreed to the Terms of Service & Privacy Policy.

You might also like

Make losing weight feel Second Nature

The first step on your Second Nature journey is to take our health quiz.

Hand holding phone

Write a response

As seen on

The GuardianThe TimesChannel 4The Sunday Telegraph
Evening Standard