The answer is that it depends on several factors – why we snack, what we eat and how and when we do so.
Almost everyone snacks, but often not because of hunger. Cues are one of the most powerful reasons we feel a sudden urge to eat. Supermarket designers know this, which is why tempting snacks are carefully positioned – for example, as we enter the shop or while we're waiting to pay. Seeing someone else enjoying a food you love is another trigger.
Snacking can also be a form of avoidance: we eat something, telling ourselves we need energy, but really so we can delay starting an unpleasant or challenging task.
We may also reach for food because we mistake thirst for hunger. This is easily done because symptoms of mild dehydration – headache, fatigue, distractibility – resemble signs of hunger.
So it can be helpful to learn to recognise the reasons you're craving food, and distinguish emotional signals from true hunger. Here's how to manage your snacking habit.
If you feel a sudden urge for a snack, stop. Consider whether your desire was triggered from within (feeling light-headed or hearing your stomach growling) or without (seeing someone else eating, noticing a delicious smell). If you're responding to an environmental trigger, wait 20 minutes. If you still feel hungry, enjoy a healthy snack.
Learn to distinguish sensations of hunger from thirst. If you're not sure, try drinking a glass of water. If you still feel unsatisfied, a wholesome snack is a good idea.
Whenever you eat, focus on the food instead of eating while multitasking. Jean Kristeller at Indiana State University and colleagues at Duke found that mindful eating – focusing fully on the taste, scent and satisfaction of the foods you eat – not only increases enjoyment but makes it easier to control food intake.
Choose wholesome foods, and make sure you keep them readily available, preferably in place of sugary snacks. Current dietary guidelines suggest fresh fruit, nuts or plain yogurt. Even better, follow Berkeley professor Michael Pollan's suggestion: don't eat anything your grandmother wouldn't recognise as food, or anything with more than five ingredients.
Snack earlier in the day. A study by Daniela Jakubowicz at Tel Aviv University found that overweight women who ate the bulk of their calories early in the day lost more weight than those who ate them later.
Finally, if you have children, encourage a habit of three regular, balanced meals a day and don't offer sugary additive-laden foods as a 'reward' for eating savoury foods or for good behaviour. Encourage them to recognise and tell you when they're hungry. Offer them choices, making sure all options are wholesome and healthy.