The Question
I eat dinner at 7 p.m. and go to bed at 11 pm. How bad is it to snack at night if I am trying to lose weight? What's the best food to snack on if I'm hungry after dinner?
The Answer
Eat dinner early. No snacking after dinner. If you've been on a weight-loss diet, this is advice you've probably heard.
It's thought that eating late in the evening will slow down weight loss or, worse, pack on a few pounds. But will it?
Many experts say no. Conventional wisdom holds that calories are calories, regardless of when you eat them.
In other words, if your body needs, say, 1900 calories, eating 500 of them at 6 p.m. or 9 p.m. won't make a difference to your weight. Weight gain is caused simply by eating more calories than your body uses.
Does the timing of calories matter?
Growing evidence, however, suggests that weight gain is not just about "calories in versus calories out." Weight-loss studies have shown that the timing of meals does influence how much weight people lose.
One trial, published in 2016, found that among 80 overweight women, those who ate half of their daily calories at lunch lost 25-per-cent more weight than participants who consumed them at dinner.
Two other studies discovered that dieters who ate a big breakfast (700 calories) and a small dinner (200 calories) were more successful at losing weight than were those who did the opposite.
The theory that's gaining ground is that weight control is linked to the body's circadian rhythm, the 24-hour cycle that regulates calorie burning, hunger hormones, digestion and metabolism of fat and glucose among many other bodily processes.
In other words, your body is programmed to burn fat at certain times of the day and store it at others.
Scientists believe that a regular eating schedule – and sleep schedule – is necessary to keep our internal clocks in sync. (We have different internal clocks in every organ in the body.)
Disturbing these clocks by eating late at night, for example, can mess up metabolic function and influence whether consumed calories are burned or tucked away as fat.
Eating more of your calories early in the day has also been tied to lower a level of ghrelin, a hormone that stimulates appetite and promotes fat storage.
To be fair, we're not talking about eating an apple or a few nuts after a healthy dinner. There's no research to suggest that eating a small, calorie-controlled snack at night will impede weight-loss efforts.
In fact, the right late-night snack may even benefit your metabolism.
According to a review published in the journal Nutrients in 2015, eating a protein-rich snack near bedtime can enhance muscle-protein synthesis while you sleep.
That's a good thing since low-calorie dieting can cause you to lose some muscle along with body fat. Holding onto muscle helps maintain your resting metabolism, the rate at which your body burns calories to perform its basic functions.
Extra dietary protein also enhances the muscle-preserving effect of resistance exercise, which I recommend adding to your weight-loss program.
It's possible, too, that knowing you have a structured after-dinner snack can prompt you to consume fewer calories at your evening meal.
The key, then, is to eat a small snack, not a meal's worth of calories.
Depending on what time you ate your evening meal, though, you may not need an after-dinner snack.
Know your trigger: Hunger, habit, or something else?
Before you head to the fridge, ask yourself if you are really hungry. Has it been a few hours since you ate dinner? Is your stomach grumbling?
Or, do you want something to eat because you're bored or anxious? Or are you stressed out and need to eat to unwind?
Are you simply craving ice cream because you know it's in the freezer? The thought of hard-to-resist treats can bring on a snack craving.
Perhaps your desire to snack at night is driven by a well-ingrained habit of munching while watching television or surfing the Web.
Consider your sleep habits, too. Are you staying up too late and skimping on sleep? Not getting enough sleep (seven to nine hours a night) can drive hunger and cravings by raising ghrelin.
If you do feel hungry after dinner, consider what you ate at that meal, and earlier in the day, too.
Do your meals include protein (e.g., poultry, fish, lean meat, eggs, dairy, tofu, legumes) and fibre-rich foods (e.g., whole grains, legumes, fruit and vegetables), both which can help prevent hunger pangs before bed?
If your meals are satisfying, you may still get hungry later in the evening, especially if you eat dinner early. If so, plan for a snack. Doing so doesn't need to derail your weight-loss efforts.
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What to snack on
Limit your nighttime snack to 100 to 150 calories, enough to take the edge off hunger. To stay within your daily calorie target, you may need to move some calories from earlier in the day.
Choose protein-rich snacks that help you feel satiated and supply your muscles with amino acids.
Smart choices include plain Greek yogurt with a handful of berries, an ounce of hard cheese and 15 grapes, a hard-boiled egg and raw vegetables, a half-cup of cottage cheese mixed with a quarter-cup of pineapple, or an 85-gram tin of flavoured tuna on two whole-grain crackers.
Or, try 100 calories worth of nuts: 20 almonds, 11 walnut halves, 10 pecan halves or 35 pistachios. (Pistachios in the shell take longer to eat, too.)
Avoid snacks made from refined starches and added sugars such as crackers, pretzels, cookies and cereal bars. These foods spike your blood sugar and insulin and, quite frankly, don't fill you up.
Don't snack out of the package. Measure your snack and put it on a plate or in a bowl. Doing so will prevent you from mindless eating and overeating.
To stay on track, don't keep tempting treats in the house. Sooner or later, those bite-size brownies or salt-and-vinegar chips will call out your name, likely when you're tired or stressed, and your defences are down.
Leslie Beck, a registered dietitian, is based at the Medisys clinic in Toronto.