Most of us don’t think twice about an extra biscuit with our tea, grabbing a sugary coffee on the go, or a midweek takeaway treat.
But new research suggests those small daily indulgences could be doing more than just expanding your waistline – they may also be speeding up ageing and shortening your life.
Scientists say that simply cutting your daily calorie intake by around 10 to 15 per cent could improve heart health, blood sugar control and blood pressure, all of which are linked to a lower risk of age-related disease.
The findings come from a major US study known as CALERIE (Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy), published in the American Journal of Clinical Nutrition.
In the study, 143 healthy adults attempted to reduce their calorie intake by 25 per cent over two years, while a comparison group continued eating normally.
In reality, participants achieved an average reduction of about 12 per cent – but researchers say that was still enough to produce meaningful health benefits.
Those in the calorie-restricted group saw lower blood pressure, improved insulin sensitivity, reduced cholesterol levels and around 10 per cent weight loss.
Crucially, these changes were seen in people who were not overweight to begin with.
Two hundred calories is roughly equivalent to a large glass of wine, a packet of crisps or a glazed doughnut
Dr Sai Krupa Das, senior scientist at Tufts University and one of the study authors, said the results were encouraging because the level of restriction was realistic.
‘The most exciting part is that we saw these benefits with only a moderate level of restriction that’s feasible for most people,’ she said.
For someone eating around 2,000 calories a day – the NHS guideline for an average adult woman – that means cutting just 200 calories daily.
That’s roughly equivalent to a large glass of wine, a packet of crisps or a glazed doughnut.
Researchers say the reduction doesn’t have to be strict or extreme, and people can spread it out across the week or make small swaps, such as cutting snacks or sugary drinks.
Scientists believe the benefits may come down to how the body processes energy.
When calorie intake drops, the body becomes more efficient at turning food into energy and may produce fewer ‘reactive oxygen species’ – unstable molecules linked to cell damage, ageing and diseases such as cancer and Parkinson’s.
Tests on participants suggested those cutting calories had lower levels of these molecules compared with the control group.
Experts stress the findings don’t mean calorie restriction is a guaranteed path to longer life but they do strengthen the link between eating patterns and healthy ageing.
The CALERIE researchers are now following up participants years later to see whether the early health improvements have lasting effects and whether people continued the calorie-reduction habits after the study ended.
Scientists say moderate calorie reduction may be safe for many healthy adults, but it is not suitable for everyone.
Those advised to seek medical guidance first include people over 65, pregnant women, children and teenagers, people with low body weight and those with medical conditions affecting bone density or requiring medication.
Dr Das said online tools can help people estimate their current intake before making small reductions. ‘Use that, and then take off 10 or 20 per cent,’ she said.
The findings come as obesity rates continue to climb.
In England, nearly two-thirds of adults are now overweight, with more than a quarter classed as obese – around 14 million people.
The condition costs the NHS more than £11 billion a year, alongside wider economic losses linked to ill health and reduced productivity.
At the same time, fewer than a third of adults eat the recommended five portions of fruit and vegetables a day, and around one in three do not get enough physical activity.
