We are often told not to eat between meals, and there is a general perception that snacking is unhealthy. But, as usual when it comes to food, temptation prevails.
Snacking is very common, and increasingly so. In the early 1970s, for example, US adults consumed about 18 per cent of their total calories in snack form. By 2010, that had . Similar numbers have been recorded in the UK, and .
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This article is part of a series on nutrition that delves into some of the hottest trends of the moment. Read more here.
Given how common snacking is, it would be nice to know whether the received wisdom is true. But research on the health effects of snacking has produced a dog’s dinner of results. Some studies have found that, as expected, snacking has negative health consequences. But others have .
To get a clearer picture, earlier this year, at King’s College London, who is also chief scientist at the Zoe nutrition app, and her colleagues, they had gathered as part of an experiment carried out in 2018 and 2019, in which around 850 participants recorded everything they ate and when they ate it across two to four days. They were also tested on a range of measures of cardiovascular health, such as levels of blood fats and glucose.
Berry and her team found that 95 per cent of people in the study snacked, which they defined as consuming food or drink at least 30 minutes before or after main meals. The average number of snacks per day was 2.28, and around 24 per cent of calories were consumed in snack form. The researchers also devised a measure of the nutritional quality of snacks, called the snack diet index.
Snacking: good or bad?
Their overall finding was somewhat surprising: snacking, per se, isn’t associated with negative health outcomes. This contradicts one of the most common arguments against snacking. “There are many people who say having multiple eating events throughout the day is bad for you,” says Berry. “You need to give your body a rest.”
Yet her team’s results suggest this isn’t the case. “There was no difference in health outcomes depending on the number of eating events,” she says. “If you had three or if you had six, it didn’t matter.”
But snacking isn’t a free lunch either. It depends on what you eat and when. Unsurprisingly, people who snaffled poor-quality snacks, such as biscuits, crisps and cakes, and/or ate after 9pm were worse off health-wise than those who didn’t snack at all or who snacked on nuts, seeds, fresh fruit and vegetables.
Research on the health effects of snacking has produced a dog's dinner of results
“What seems to matter is the quality of the snack – obviously – and the timing,” says Berry. The effect of late snacking may be due to the disruptions in circadian rhythms associated with eating at the wrong time.
But here’s the thing: people who snacked on healthy foods and didn’t snack late were better off than non-snackers. Snacking on fruit, vegetables, nuts and seeds earlier in the day is associated with a healthier weight and body mass index.
That may be because well-timed, healthy snacks reduce hunger and overall calorie intake. In 2022, a team at Winona State University in Minnesota with giving first-year college students – who often gain weight after starting university – a snack 90 minutes before their evening buffet meal. They either got 190 calories of walnuts, a 190-calorie gummy candy or no snack. The snackers ate fewer calories’ worth of food in the subsequent meal, and less overall, compared with the non-snack group, even with the snack factored in. The walnuts also proved more effective than the candy at reducing calorie intake. This suggests that eating a wholefood snack shortly before meals can reduce our overall energy intake.
Another thing to consider when reaching for a snack is why you are doing it. Research shows that most of us rather than hunger. “If you don’t need the energy, that’s where it becomes a problem,” says Berry.
at Purdue University in Indiana concurs with this view. He says our ability to gauge energy intake isn’t precise, “so in the current environment where foods are abundantly available and social custom often dictates that we eat when we’re not hungry, that tends to be the problem”.
This means that the planning – or not – of snacks is important. “When snacking is a planned eating event, then compensation [for calories at mealtimes] seems to be stronger,” says Mattes. “When it’s an unplanned eating event, generally it’s less well compensated and so the energy from those types of snacks tends to add more to total daily energy intake.”
The take-home message is that snacking isn’t automatically bad for your health – and can be positive. “If you are a grazer, as long as you’re grazing on healthy food and not grazing late at night, current evidence would support that this can be part of a healthy, balanced dietary pattern,” says Berry. “It’s a simple dietary strategy that can improve your health.”
“I think we have to accept that people want to eat more times per day than they used to,” says Mattes. “The real goal now is to understand how to incorporate it in a way that isn’t problematic.”
