GP says people with weight loss goals make common mistake

And it isn’t to do with food intake, or exercise

A GP has highlighted a common mistake many people make when trying to lose weight, and it’s not actually related to diet or exercise. While the basic principles of weight loss are well understood, one GP warns that most people overlook a crucial element that can significantly aid weight loss.

The twin pillars of weight loss and healthier living are widely accepted as eating less and exercising more, but there’s one habit that is consistently neglected. Dr Dominic Greenyer, director and GP at The Health Suite, emphasised that sleep can have a greater impact than many appreciate.

He explained: “As a GP I frequently see patients doing ‘all the right things’ nutritionally, yet struggling with weight, energy, or metabolic health. Usually, the underlying cause for this is suffering from a disrupted sleep pattern.”

Our bodies operate on a 24-hour internal clock, often known as your circadian rhythm, which regulates not just sleep, but also how efficiently you burn fat, regulate blood sugar, and control appetite, a fact that many fail to recognise. Dr Greenyer added: “Sleep timing strongly affects how much you eat and when you want to eat it. Leptin, a satiety hormone, and ghrelin, a hunger hormone, normally follow a healthy rhythm overnight.

“But when sleep is shortened or irregular, leptin levels fall whilst ghrelin rises, increasing hunger, reducing fullness, and driving cravings for calorie-dense foods.”

This means that individuals grappling with disrupted sleep patterns frequently experience a surge in late-night snacking, intense cravings for sugary or refined carbohydrate-rich foods, and struggle to maintain dietary modifications despite their best intentions.

Late-night snacking proves especially detrimental to weight-loss efforts, as our bodies are considerably less efficient at metabolising fat during nocturnal hours. Dr Greenyer explained: “Research shows resting metabolic rate is lowest during the biological night (when core body temperature drops) and highest later in the biological afternoon and early evening.

“Fat oxidation follows a circadian rhythm, meaning your body is simply less efficient at burning fat late at night. Controlled laboratory studies have shown that late evening meals lead to higher overnight glucose levels and delayed fat burning, even when calories are matched.”

Disrupted sleep patterns can also trigger cortisol spikes, potentially making weight-loss efforts more challenging than necessary. Dr Greenyer noted: “Normally high in the morning and low at night, cortisol becomes dysregulated when sleep timing is poor. Elevated evening cortisol, often driven by stress, screens, or poor sleep hygiene, promotes visceral fat storage and further disrupts sleep quality.”

Yet even armed with this knowledge, transforming sleep habits and routines can prove more difficult than improving diet or fitness levels. For those looking to enhance their sleep quality, Dr Greenyer suggests adopting six key practices.

He explained: “The best habits to incorporate into your everyday routine include having consistent sleep and wake times, even on weekends, getting daylight exposure in the morning, bringing your dinner time forward, reducing evening screen exposure, exercising in the day rather than in the late-evening, and trying to get seven to nine hours of sleep most nights.”