From ‘hidden’ calories to stress – the 12 reasons you’re not losing weight despite being in a calorie deficit

IF you’re struggling to lose weight despite sticking to a calorie deficit, you’re not alone.

A calorie deficit is often touted as the key to weight loss – it's when you consume fewer calories than you burn in a day.

Calories are the energy you get from food, fuelling everything from breathing to exercise.

When you're in a calorie deficit, your body draws on stored energy (primarily fat) to make up the difference, which can lead to weight loss over time.

To reach a calorie deficit, you need to either eat fewer calories, increase physical activity or do a combination of both.

For example, if your calories are 2,000 per day, reducing to 1,500 calories or boosting physical activity by 500 calories would create a deficit.

But creating a calorie deficit isn't a one-size-fits-all approach.

Factors like age, how active you are, health conditions and metabolic rate – the speed at which your body burns calories at rest – can all affect your personal calorie needs.

Sophie Trotman, Nutritionist atFrive, shared how hidden calories, metabolism quirks and lifestyle factors can all play a role in slowing your progress.

1. Hidden calories

Sometimes, calories sneak in through sauces, drinks and even healthy snacks, making it easy to underestimate your intake, said Sophie.

“These “hidden”; calories add up, reducing the effectiveness of your calorie deficit,” she explained.

“Studies have found that people often underestimate their daily calorie intake, especially with high-calorie foods like sauces and oils, by around 20 per cent to 50 per cent on average.

“To stay on track, use a food diary or app to record everything, including condiments and beverages, so that no calorie goes unnoticed.”

2. Miscalculating portion sizes

Portion sizes can be deceiving, and even a tiny miscalculation can add hundreds of calories.

Sophie said: “Research shows that people tend to underestimate portion sizes – which is even more likely when you're hungry or in a rush, leading to eating more than planned.

“Regain your power and combat this by using measuring tools or a digital scale to keep your portions accurate or consider ready-to-eat meal prep services to help you stick to your calorie goals more effectively.”

3. Metabolism changes

Metabolism isn’t static; it can slow down over time, especially with prolonged calorie deficits, said Sophie.

She added: “Studies back this up, showing that as you lose weight, your resting metabolic rate (RMR) can also decrease – which we don’t want.

“To support metabolism, try incorporating strength training to build muscle, as muscle tissue burns more calories than fat, even at rest.”

4. Stress

As stress levels rise, so does the stress hormone cortisol, which can contribute to weight gain, especially around the abdomen.

Sophie advised: “High cortisol levels increase cravings for high-fat, high-sugar foods, like cakes, chocolate and chips, making it harder to maintain a calorie deficit.

“Practising stress management techniques, such as deep breathing or yoga, can help control cortisol levels and support weight loss.”

5. Hormonal imbalances

Hormonal issues like thyroid dysfunction or insulin resistance can impact weight loss, making it harder to lose pounds despite a calorie deficit, according to Sophie.

She said: “Conditions such as hypothyroidism slow down metabolism, reducing calorie burn.

“If you have or suspect that one of these conditions may be blocking your progress, book an appointment with your healthcare provider.

“They’ll be able to test and manage any hormonal issues that you may be dealing with more effectively.”

6. Poor sleep

If you’re skimping on sleep, it could be slowing your weight loss progress, with research finding that poor sleep disrupts hunger-regulating hormones like leptin and ghrelin.

The result? Increased cravings and overeating the next day, said Sophie.

She added: “In fact, participants who slept 5.5 hours per night experienced more fat retention and increased cravings compared to those who slept 8.5 hours.

“So, the next time you’re tempted by a late-night, think again.

“Prioritising seven to eight hours of quality sleep can make a surprising difference in controlling your appetite and, consequently, weight loss.”

7. Lack of muscle mass

Muscle burns more calories even when you’re at rest, so if your muscle mass is on the low side, losing weight can feel like an uphill battle.

But here’s the good news, said Sophie: strength training is your metabolism’s best friend.

She advised: “Just a couple of weekly weight sessions at the gym can work wonders, helping you build lean muscle and giving your resting metabolic rate a serious boost!”

8. Overeating after workouts

Feeling ravenous after a workout? It’s common – after all, you’ve just burned up loads of energy.

Unfortunately, it can also lead to unintentional overeating, which might undo all your hard work, warned Sophie, not to mention that it’s easy to overestimate the amount of calories burned while exercising.

She recommended: “Avoid this by having a balanced post-workout snack and pay attention to portion sizes when it comes to your main meals to keep you on track.

9. Underestimating liquid calories

It’s easy to overlook the calories in drinks like lattes, smoothies, alcoholic beverages or even juices.

Sophie said: “Those sneaky liquid calories can add up quickly and tip you over your daily limit, so make sure to include drinks when tracking your calories and choose lower-calorie beverages to keep you within your calorie goals.”

10. Exercise mismanagement

Like most things, not all workouts are created equal, and focusing too much on cardio without strength training can actually limit your progress, said Sophie.

She added: “Seek the advice of a personal trainer or create a more balanced routine by incorporating strength training with cardio to enhance your results and support long-term weight management.”

11. Medication

Certain medications, like antidepressants, antipsychotics and hormonal therapies, can all play their part and, frustratingly, make weight loss even more challenging.

Sophie explained: “From slowing down your metabolism to increasing your appetite, these common side effects can turn your weight loss journey into an uphill battle.

“If you suspect your medication is affecting your weight loss, talk to your local GP.

“They'll be able to advise you and help identify possible solutions, including making adjustments when it comes to doses or finding alternative medications.”

12. Water retention

Water retention can mask your progress on the scale, even if fat loss is happening and your body composition is changing.

Sophie said: “According to research, high sodium intake, stress and hormonal changes can all contribute to water retention, creating the illusion of stalled weight loss.

“Believe it or not, drinking water can actually help your body hold onto less water.

“When your kidneys are working at their best, they're better able to flush out extra sodium and water, reducing water retention.

“Stay hydrated and drink six to eight glasses of water daily to see your results and hard work in all its glory.”

So how do you know if your deficit is working?

Progress isn’t always about the scale – it’s often the small victories that count, said Sophie.

Signs like shrinking body measurements, boosted energy levels, and a better overall mood can all indicate that your calorie deficit is paying off.

She added: “Pay attention to how your clothes fit, how energetic you feel and your general outlook. These small yet powerful shifts indicate that your body is responding positively to the changes you’re making.

“Sticking to a calorie deficit isn’t always as straightforward as it sounds, but understanding the common hurdles, like hidden calories, metabolism shifts and lifestyle factors, can make all the difference.

“With careful tracking, tweaks to your routine and a bit of good old-fashioned patience, reaching your goals becomes much more achievable.

“Progress can take time, but small wins are a sure sign you’re on the right path.”

The 5 best exercises to lose weight

By Lucy Gornall, personal trainer and health journalist

EXERCISE can be intimidating and hard to devote yourself to, particularly at this time of year, when the rain is as relentless as your craving for carbs.

So how do you find the right workout for you?

As a PT and fitness journalist, I’ve tried everything.

I’ve taken part in endless fitness competitions, marathons and I maintain a regime of runs, strength training and Pilates.

Fitness is so entrenched in my life, I stick to it even at Christmas!

The key is finding an activity you love that can become a habit.

My top five forms of exercise, especially if you're trying to lose weight, are:

1. Walking
2. Running
3. Pilates
4. High-intensity interval training (HIIT)
5. Strength training