The real reasons you’re not losing weight

Scientists are fast uncovering a wealth of hidden factors influencing how your body metabolises food. Photo / 123RF

You’ve cut out croissants, biscuits and booze and even switched to black coffee and started exercising. So why can’t you shift those stubborn pounds? It’s time to look beyond your calorie tracker and weekly workouts for the answer. Scientists are fast uncovering a wealth of hidden factors influencing how your body metabolises food.

“It’s not just what you eat, but also how you eat matters and who you are,” says Dr Sarah Berry, associate professor in the Department of Nutritional Sciences at King’s College London and chief scientist at ZOE nutrition programme. “For example, your age, sex and gut microbes can all impact how you respond to food, as well as how much sleep you’ve had and the time of day that you’re eating.”

Read on to discover the surprising reasons you struggle to stay slim and simple, science-backed solutions.

You’re eating too late

Do you regularly eat dinner after 8pm or snack through the evening? You could be disrupting your body clock, driving up your appetite and encouraging weight gain. “The time of day you eat your food has an impact,” says Dr Berry.

“If you eat carbohydrates earlier in the morning, you’re likely to have a lower blood sugar response than eating them later in the day.”

When your blood sugar spikes, you’re more likely to store excess energy as fat. It also stimulates your appetite. A study in Cell Metabolism found that late-night eating made people hungrier the following day.

“The evidence shows if you are intermittent fasting, cutting out late-night eating is far more effective than skipping breakfast,” Berry says.

Fix it: “Cut out evening snacks,” says Dr Berry. “Avoid eating between 8pm and 8 or 9am to rest your metabolic processes and gut microbes. Research suggests that fasting can increase the diversity of your gut microbiome, which is linked to better metabolic health (including low blood sugar and cholesterol) and weight loss.”

Do you regularly eat dinner after 8pm or snack through the evening? You could be disrupting your body clock, driving up your appetite and encouraging weight gain. Photo / Mae Mu, Unsplash

You’re at the gym three times a week

Working out religiously but not seeing results? Consider how active you are outside the gym. “Scheduled exercise is not the biggest lever you can pull for losing weight,” says Kevin Garde, a nutritionist specialising in fat loss at London’s Bodyscan clinics.

“There are 168 hours in a week, so if you’re doing three one-hour workouts, you’re only exercising for 2 per cent of the week.”

Fix it: “Being active throughout your day has a cumulative effect on fat loss,” says Garde. “By walking 10,000 daily steps, that’s 200 extra calories burned, equating to 9.5kg of body fat a year!”

You’re eating too fast

Bolting down your lunch? “The faster you eat, the more rapidly sugar enters your bloodstream,” says Dr Berry. “It outpaces the speed at which insulin can remove it. Any dysregulation in blood sugar control can impact processes involved in metabolic health and weight change. People who eat faster tend to have a higher weight and energy intake than people who eat slowly.”

Another study, published in the British Nutrition Journal, found people taking longer to eat saw a more blunted blood sugar response.

Fix it: Put down your cutlery between mouthfuls. “I’m always telling my children not to wolf food, listen to your hunger signals,” says Dr Berry. “It’s good advice for everyone.”

Your calorie tracker is cheating

Your smartwatch just congratulated you on burning 400 calories – but is it right? “Exercise trackers can overestimate calorie burn by 16 to 40 per cent, so never rely on these devices,” says Garde. “Most base their estimate on someone with average muscle mass so, if you have a lower level, you’ll burn fewer calories.”

Using a tracker can mean you ‘eat back’ the calories you’ve burned. “An hour of resistance training might burn 300 calories, while a Pret chicken and avocado sandwich contains around 480 calories,” says Garde.

Fix it: Use calorie counts as a guide and see if they’re validated in real life. “If your tracker says you’re in calorie deficit but you fail to lose weight, either the calculator estimate is wrong, you’re consuming more food, or you’re being less active – or all three!” says Garde.

You’re celebrating a special day

It’s not only negative emotions that can trigger us to overeat. Positive feelings like excitement can stimulate appetites too. “Feeling stressed and excited have the same physiological manifestations – increased heart rate, palpitations, sweaty palms,” says psychologist Dr Meg Arroll, author of new book Tiny Traumas: When You Don’t Know What’s Wrong, but Nothing Feels Quite Right.

“The body always aims to bring itself back to homeostasis and one way to do this is by eating. Any situation where emotions are running high can up the chance of tucking in.”

Fix it: Try Arroll’s “triple A” approach: awareness, acceptance, action. “Help your body re-balance without eating by using deep, diaphragmatic breathing exercises.” Inhale through your nose for four seconds. Hold your breath for two. Exhale for six.

It’s your hormones

Hot flushes and brain fog? Menopause triggers changes in your gut microbiome and metabolism. “Postmenopausal women tend to have higher blood sugar responses, higher blood fat responses and high inflammatory responses after a meal,” Berry says.

“They have a different microbiome composition, higher levels of fat around the tummy and tend to feel hungrier, despite eating the same amount as pre-menopause. These factors all occur because oestrogen levels decline.”

Fix it: Reduce your refined carbohydrate intake to limit blood sugar spikes which increase obesity risk, Berry says. “Restrict heavily processed foods, increase wholefoods and the diversity of plant-based foods you eat. Don’t be afraid to have unprocessed, high-protein or high-fat, plant-based foods such as avocado and nuts – they help maintain a healthy weight.”

You drop off with the TV on

Dropping off with your screen on can play havoc with your metabolism, chronobiologists say. Photo / Atul Vinayak, Unsplash

This bedtime habit can play havoc with your metabolism, warn chronobiologists. “The blue light emitted may increase your alertness and push your circadian clock later in time, making it harder to fall asleep at night,” says Dr Vikki Revell, senior lecturer in transitional sleep and circadian physiology at the University of Surrey.

Sleeping with the TV on is not as restful. “Stage 1 sleep is very light so it can be easily disturbed by TV sound. Chronic insufficient sleep impacts on your appetite and metabolism, increasing food intake and decreasing energy expenditure. Long-term, disturbed sleep is associated with an increased risk of developing metabolic syndrome (a combination of diabetes, high blood pressure and obesity).”

A study in the Journal of the American Medical Association found that sleeping with artificial light, including from TV, was linked to increased obesity risk.

Fix it: “In the hour before bed, avoid screens and all bright light,” says Dr Revell. “Use the night-shift setting on electronic devices to minimise the blue light exposure.”

You’ve gone plant-based

Fake meats, non-dairy desserts… “healthy” plant-based staples may actually be sabotaging your weight loss efforts, warn nutrition scientists. Though marketed as wholesome, they’re actually ultra-processed foods (UPFs), high in energy, sugar and saturated fats.

“Vegan doesn’t necessarily mean healthy,” says nutritionist Jenna Hope. “The processing methods that UPFs go through often break down ingredients’ cell structures, meaning more energy can be stored in the body. Additionally, UPFs typically release their sugars into the blood quicker, which can contribute to a blood sugar roller-coaster.”

Research by the US National Institutes of Health found people on ultra-processed diets ate 500 more daily calories, gaining an extra 2lb (0.9kg) in two weeks, against those eating a minimally processed diet containing the same nutrients.

Fix it: Switch to wholefoods such as beans, pulses, nuts and seeds. “A wholefood, plant-based diet is associated with a reduction in saturated-fat intake and increase in fibre which can aid weight management,” says Hope.

You’re relying on a ‘magic bullet’

Your friends swear by intermittent fasting, but it’s not working for you? Be honest about your eating, says Aisling Pigott, registered dietitian and spokesman for the British Dietetic Association. Are you overdoing it during your eight-hour “eating window”?

“So often, we’re drawn to quick-fix solutions, forgetting the importance of balance,” says Pigott. “Lots of us have complicated relationships with food, so while time-restricted eating can work well for some, for others, the idea of ‘free foods’ can fuel overeating.”

Fix it: “When we look at making our meals more about nourishing our bodies as opposed to what we can cut out, we often find our weight stabilises,” says Pigott. “Eat small portions of carbs, protein, fruit and veg in every meal to feel more satisfied.”

You are battling your ‘set point’

“Your brain hates it when you lose weight,” says Giles Yeo, professor of molecular neuroendocrinology at the MRC Metabolic Diseases Unit at the University of Cambridge. “It sees it as reducing your survival chances, so attempts to drag you, kicking and screaming, back up to what your previous weight was.”

Your brain’s first response is to make you hungrier, says Yeo, so try eating foods that make you feel full. “Foods that take longer to digest travel further down the gut, meaning more gut hormones are released, so you feel fuller,” he explains. “Two foods fit this criterion. The first is protein, from any source: tofu, beans, fish, meat.

“It’s chemically the most complex of the three macronutrients so takes longer to digest and more energy to metabolise, making you feel fuller. The second food is fibre, which has the same effect. It can be from a variety of sources – the more the merrier.”

Fix it: “Whatever diet you’re following, aim to eat 16 per cent of your energy from protein and as much fibre as you can,” says Yeo. “We probably need to double the amount we’re having to 30g a day.”