Opinions vary about whether snacking is healthy or unhealthy.
Some people think snacking is healthy, while others believe that it is unhealthy and can lead to weight gain.
We have reviewed the research and evidence.
Here is a summary of how snacking affects health.
Firstly We Define Snacking
A snack is a small portion of food or drink or a light meal, especially one eaten between regular meals.
People often mean processed, high-calorie foods like chips and cookies when they use the phrase “snack foods”.
However, “snacking” simply means to eat or drink something between meals, regardless of whether the food is healthy or not (1).
The primary motivation and reason for snacking is hunger. Other factors such as location, social environment, time of day and food availability affect whether we snack or not.
In reality we often eat a snack because there is tasty and appealing food available, even if we are not hungry.
Looking at the research, one study, when overweight and obese people were asked why they chose unhealthy snacks found that the most common response was temptation, followed by being hungry and feeling low on energy (2).
Another piece of research found that both the desire to snack and snacking’s effects on health appear to be highly individualized. Factors that influence snacking include age and beliefs about whether snacking is healthy or not (3).
Snacking refers to eating or drinking outside of regular meals. Reasons for snacking include hunger, food availability and environmental and social cues.
Does Snacking Boost Your Metabolism?
Although it’s been suggested that eating every few hours will increase your metabolism, the evidence does not support this.
Research has shown that frequency of meal has no significant effect on how many calories you burn (4).
In one study, researchers compared the responses of people who consumed an equal number of calories in either two or seven meals per day. They found no difference in calories burned (5).
In another study, obese people who followed a very low-calorie diet for three weeks showed similar decreases in metabolic rate, regardless of whether they ate 800 calories as one or five meals per day (6).
Interestingly, one study reported that a bedtime snack may lead to a higher metabolic rate the next morning.
In this study, when active young men consumed a high-protein or high-carbohydrate snack before bed, they experienced a significant increase in metabolic rate the following morning (7).
However, this increase in metabolism would be expected, given that the snacks provided additional calories that were burned overnight. The researchers didn’t compare the effect of including these foods at meals instead.
People often believe that snacking every few hours will increase their metabolism. However, research has found that eating frequency has little or no effect on metabolism.
How Snacking Affects Appetite and Weight
Studies on snacking’s effects on appetite and weight have provided mixed results.
Snacking’s Effects on Appetite
The effect of snacking on appetite and food intake is debated and there is conflicting evidence.
One review found that although snackings may briefly satisfy hunger and promote feelings of fullness, their calories aren’t compensated for at the next meal.
The result is an increased calorie intake for the day (8).
A study of overweight men who ate a 200-calorie snack two hours after breakfast ended up eating only 100 fewer calories at lunch (9).
This means that their total calorie intake increased by about 100 calories.
In another controlled study, lean men ate either three high-protein, high-fat or high-carb snacks for six days (10).
Their hunger levels and total calorie intakes didn’t change compared to the days on which they ate no snacks, indicating that the snacks had a neutral effect (10).
In one study, when men ate a high-protein, high-fibre snack bar, they had lower levels of the hunger hormone ghrelin and higher levels of the fullness hormone GLP-1. They also took in an average of 425 fewer calories per day (12).
Another study in 44 overweight or obese women found that a bedtime snack high in protein or carbohydrates led to decreased hunger and greater feelings of fullness the next morning. However, insulin levels were also higher (13).
Based on these varied results, it appears that snacking’s effect on appetite may depend on the individual and type of snack consumed.
Snacking’s Effects on Weight
For example, a non-controlled study in 17 people with diabetes reported that consuming snacks high in protein and slow-digesting carbs resulted in an average weight loss of 2.2 pounds (1 kg) within four weeks (17).
In one study, 36 lean men increased their calorie intake by 40% by consuming excess calories as snacks between meals. They experienced a significant increase in liver fat and belly fat (19).
Interestingly, another controlled study suggests that the timing of snacks may be what makes a difference when it comes to weight changes.
This study in 11 lean women found that consuming a 190-calorie snack at 11:00 p.m. reduced the amount of fat they burned significantly more than consuming the same snack at 10:00 a.m. (20).
The mixed results suggest that weight responses to snacking probably vary by individual.
Mixed results from several studies suggest that weight and appetite responses to snacking vary by individual.
The Effects of Snacking on Blood Sugar
Many people think that it is necessary to eat frequently to maintain stable blood sugar levels throughout the day, but this isn’t always the case.
In fact, a 2014 study in people with type 2 diabetes found that eating only two large meals per day resulted in lower fasting blood sugar levels, better insulin sensitivity and greater weight loss than eating six times per day (21).
Of course, the type of snack and amount consumed are the main factors that affect blood sugar levels.
Lower-carb, higher-fibre snacks have consistently been shown to have a more favorable effect on blood sugar and insulin levels than high-carb snacks in people with and without diabetes (12, 22, 23, 24).
In a study of 20 healthy men, consuming a high-protein, lower-carb dairy snack led to lower blood sugar levels before the next meal, compared to higher-carb dairy snacks or orange juice (26).
It is not necessary to snack to maintain healthy blood sugar levels. Eating high-protein or high-fibre snacks raises blood sugar levels less than consuming high-carb snacks.
Snacking Can Prevent Ravenous Hunger in Some People
Snacking may not be good for everyone.
However, it can definitely help some people avoid becoming ravenously hungry.
When you go too long without eating, you may become so hungry that you end up eating many more calories than you need.
Snacking can help keep your hunger levels on an even keel, especially on days when your meals are spaced further apart.
However, it’s important to make healthy snack choices.
Eating a snack is better than letting yourself become ravenously hungry. This can lead to poor food choices and eating more calories than you need.
Tips for Healthy Snacking
In order to get the most out of your snacks, follow these guidelines:
Amount to eat: In general, it’s best to eat snacks that contain about 200 calories and at least 10 grams of protein to help you stay full until your next meal.
Frequency: The number of snacks you need will vary based on your activity level and how big your meals are. If you’re very active, you may prefer 2–3 snacks per day, while a more sedentary person may do best with one snack or no snacks.
Portability: Keep portable snacks with you when you’re out doing errands or traveling in case hunger strikes.
Snacks to avoid: Processed, high-sugar snacks may give you a brief jolt of energy, but you’ll probably feel hungrier an hour or two later.
When snacking, be sure to eat the right types and amounts of food in order to reduce hunger and prevent overeating later on.
Healthy Snacks to Eat
Although there are many packaged snacks and bars on the market, choosing nourishing real food is best.
It’s a good idea to include a protein source in your snack.
For example, both cottage cheese (high in protein and low in fat) and hard-boiled eggs have been shown to help keep you full for hours (27).
Here are a few other healthy snack ideas:
- String cheese
- Fresh vegetable slices
- Sunflower seeds
- Cottage cheese with fruit
Choosing healthy snacks that are high in protein and fibre helps reduce hunger and keeps you full for several hours.
So Is Snacking Good or Bad?
Snacking can be good in many cases, such as for preventing hunger in people who tend to overeat when going too long without food.
However, some may do better eating three or fewer meals per day.
In the end, it’s really a personal choice.
The most important point is that it is vital to choose healthy high protein foods which are low in fat or contain healthy mono-unsaturated fat such as almonds or cottage cheese.
These foods keep you full and satisfied for longer.