A significant proportion of adults regularly snack late at night after dinner, driven by natural biological mechanisms rather than simply a lack of willpower.
Research indicates that around one-third of people snack every night after their evening meal, while four in five young adults aged 18 to 24 say they cannot resist late-night eating. However, eating within two hours of going to bed increases the likelihood of weight gain and obesity, according to Dr Kristine Beaulieu, a dietitian who works at the University of Leeds and the University of Moncton in Canada, reports BBC.
Experts say evening cravings are partly driven by the body’s natural appetite patterns, which tend to peak later in the day regardless of how much food a person has eaten earlier.
Prof James Betts, who researches how the body processes food and energy at the University of Bath, identifies ghrelin, commonly known as the hunger hormone, as a key factor. Ghrelin levels generally rise later in the day. Although meals typically suppress the hormone, this effect is more pronounced after breakfast than after lunch or dinner.
The composition of evening meals also plays an important role. Dinners rich in protein, fibre and volume help people feel fuller for longer. Prof Betts says that skipping a nutritious or satisfying evening meal can lead to a late-night energy crash and trigger snacking. Other factors include the fear of waking up hungry and established eating habits.
Environmental cues can also contribute to the urge to snack. Prof Suzanne Higgs, an appetite expert at the University of Birmingham, explains that regular routines associated with particular settings can trigger cravings. For example, people who routinely snack while watching television may feel the urge to eat simply by turning on the TV.
Beyond physical hunger, the desire for calorie-dense foods also increases later in the day. This is largely driven by the brain’s reward system rather than the body’s actual energy needs.
Dr Beaulieu says people tend to have a stronger liking and desire for high-fat foods later in the day than for low-fat alternatives. These cravings can override feelings of fullness, even after a substantial evening meal. Foods high in sugar, fat and salt continue to stimulate the brain’s reward pathways, making late-night cravings largely a biological response.
However, evidence on whether evening snacking affects sleep remains mixed. Eating a large meal late at night can interfere with digestion and the body’s natural preparation for sleep, but the effects of lighter snacks are less clear.
Foods high in refined carbohydrates and added sugars, including white bread, white rice, biscuits and cakes, have been linked to poorer sleep quality. This may be due to sharp fluctuations in blood sugar levels and changes in the hormonal signals that regulate sleep and appetite.
Establishing a direct cause-and-effect relationship is difficult, as sleep deprivation itself can increase appetite and the desire for energy-dense foods, according to Prof Jonathan Johnston, a sleep and body clock expert at the University of Surrey.
Prof Betts also says the evidence linking late-evening snacking to disrupted sleep is inconclusive and that the effects may vary depending on how individuals respond to different foods before bedtime.
To manage evening cravings, experts recommend identifying whether genuine hunger or habit is driving the urge to eat.
If hunger is the main reason, eating more filling meals earlier in the day, particularly those rich in protein, fibre and volume, can help. For habitual snacking, changing daily routines, planning snacks in advance and avoiding distracted eating are recommended.
Watching television while eating, for instance, can lead to greater food consumption because people pay less attention to how much they eat.
Dr Beaulieu says there is no need to eliminate evening snacks altogether. Instead, keeping portions reasonable and allowing room for enjoyable foods is a more sustainable approach.
Experts recommend keeping healthier options such as fruit, yoghurt and nuts readily available. Eating small amounts of foods people crave, including chocolate, is also acceptable when done in moderation.
Keeping tempting foods out of regular kitchen cupboards can further encourage healthier choices by making nutritious alternatives easier to reach.
