The pursuit has come a long way since you tucked into a Mint Club at morning break. But when does a healthy habit become a nutritional no-no? Dietitian Laura Tilt follows the crumbs.

If your enthusiasm for snacking extends to packing crackers in your out-out clutch, you’re in good company. Snacking is a daily habitfor some 69% of Brits, according to market research group Mintel, and the food industry has responded accordingly, with a snack for every conceivable mood. But satiated isn’t all you’re feeling – a recent YouGov survey revealed that 84% of women feel guilty about between-meals eating.

Determining a healthy snacking habit is difficult, since there’s no real definition of what constitutes a snack – is it defined by the time of day,the type of food or the number of calories consumed? And when research exists across a range of populations, from healthy volunteers to those with diabetes, applying results from a single study to everyone is misleading. Yeah,the researchers are confused,too.

Snacking can help regulate appetite: ifthe gap between lunch and dinner spans more than five hours, snacking is a smart move. There’s also evidence that snacking has a more favourable effect on cholesterol and blood pressure than eating just one large meal a day. On the other hand, between-meals eating has also been linked with a higher calorie intake, weight gain and a greater risk of developing metabolic syndrome – a cluster of conditions that occur together, increasing your risk of heart disease, stroke and type-2 diabetes.

Like the small print on a box of Pop Tarts, the devil is in the detail. Snacking without adjusting the timing or size of yournext meal canresultinweight gain.But once you adjust for snack choice,the relationship between snacking and body fat usually disappears. In one study, overweight adults were found to consume more chocolate, crisps and sweets and a lower quantity of yoghurt andnuts thanhealthyweight adults,though once snack choice was accounted for,the link between BMI and snacking vanished. Timingmatters,too.

Inone small study,healthywomen consumed a specified snack of around 200 calories at either 10am or 11pm for two weeks.Although researchers found no change in calorie intake or body weight,the night-time snacking increased cholesterol levels and reduced fat oxidation, suggesting thatlate-night eating could lead to unfavourable changes in metabolic health. So what does this mean for your own snack drawer? As it stands,there’s no consensus on the ideal number of meals or snacks for good health, butit seems sensible to keep them to the daytime.

As a general guide, government recommendations suggestthat drinks and snacks combined should form no more than20% of your daily calorie intake – that’s about 400 calories out of 2,000. Make your snacks 150 to 200 calories each time and you’re good to have a couple a day. Higher-protein snacks, such as yoghurt, reduce hunger and calorie intake atthenext meal more effectively thanhigher-fat choices like chocolate,while fibrous options, such as almonds, popcornand fruit,will also fill you up.

Tuning into why you snack could be the biggestindicator of the health effects. The YouGov poll found women tend to snack more for enjoyment,to satisfy cravings or to cheer themselves up, butthis is more likely to lead to eating foods high in fat, sugar and salt. Meanwhile, snacking when hungry is associated with consuming healthy foods, and should reduce the number of snackcidents.