At first glance, when you think about eating before bed, you might immediately assume that this is an unhealthy habit. A commonly held belief is that nighttime eating is not in line with a healthy lifestyle. When thinking about nighttime eating, what comes to mind is a pajama-clad man or woman, stomach growling, staring into the refrigerator at midnight looking for something to satisfy a food craving.
What are the chances that a healthy choice is made in this scenario?
This commonly held belief goes further; that this pattern of nighttime eating is repeated and inevitable weight-gain ensues.
Will nighttime eating throw off your fitness and weight-management goals? The answer to this question is possibly, but it depends. Perhaps there may even be some benefits.
In this article, we’ll go through…
- Commonly held beliefs related to night-time eating.
- The important nutrients to consider.
- Night-time eating and your age; does it matter?
- The link with obesity.
- How exercise plays a role.
- Protein synthesis and muscle formation.
Why is night-time eating considered to be so bad for you? To delve further into the issue, there are more specifics to consider.
Where did this commonly held belief come from?
Research is showing that a link exists between eating at night and weight gain. This likely stems from the fact that eating later in the day may be detrimental as it primarily increases the number of chances a person has to eat. If the number of eating chances or ‘meals’ a person consumes increases, then your total caloric intake likely follows suit. After all, if total calories in are higher than total calories out (burned), weight gain is inevitable.
Things, however, are not as straightforward as they might seem.
It is true that the scenario of too many calories in versus not enough calories expended causes weight gain, but when it comes to the timing of meals, however, and eating into the evening, research supports that the type of nutrients you take in is a very important factor to consider.
Large Meals in the evening are Linked to Health Risks
Consuming large meals or the majority of nutrients late in the evening, are linked to some negative consequences including an increased risk of obesity and other cardiometabolic diseases. Studies have demonstrated that shift workers, who consume the majority of nutrients in the evening, tend to have a “higher prevalence of overweightness, abdominal obesity, elevated triglycerides, dyslipidemia, impaired glucose tolerance, and decreased kidney function, compared with daytime workers”.
Not all eating in the evening should be looked upon as bad for a person’s health. When food choices at night favor ‘small, nutrient-dense, low energy foods and/or single macronutrients’, detrimental effects may not be observed.
Research supports that single nutrients to consider include high-quality protein such as whey and casein, as well as carbohydrates. It is important also to consider the size (or calorie content) of what you are taking in.
In other words, eating in the evening under certain restrictions of specific nutrients while monitoring total calorie intake, may not be harmful to your weight loss goals, and may, in fact, have some health benefits.
Consider these Nutrients
From a nutritional standpoint, when planning meals for the day, certain nutrients should be considered when eating into the evening. A study of active college-aged men showed that intake of whey protein, casein protein or carbohydrates into the evening hours had a favorable effect on next-morning resting energy expenditure.
Participants in this study were given a single dose of whey protein, casein protein, carbohydrate or a non-energy-containing placebo. Measurements of satiety, hunger, desire to eat and resting energy expenditure were taken the next morning. It was found that resting energy expenditure was ‘significantly greater after consumption of the whey protein, casein protein, and carbohydrates’ when compared to placebo.
In other words, consuming whey protein, casein protein or carbohydrates in the evening had a favorable effect on the caloric expenditure of these young men at rest the following day.
This study lends support to the notion that simple and specific nutrients in the evening may be beneficial in a young and healthy population and therefore may support a healthy metabolism.
Metabolism is an important factor with regard to body composition, as a person with a larger metabolism will require more energy than someone with a small metabolism and this is directly linked to Lean Body Mass. Simple nutrients in the evening such as whey, casein, and carbohydrate may be considered to offer benefits in this way by increasing resting energy expenditure and therefore may have positive effects on metabolism.
Let’s Talk about Protein
Discussing protein specifically, protein intake and maintaining a healthy skeletal muscle mass must be included in a discussion around nutrient timing.
As previously described in a young population above, these effects of overnight protein administration improving muscle protein synthesis were also replicated in an elderly population. In this study, 16 healthy elderly men were given a single dose of casein protein or placebo during sleep, and measurements of dietary protein digestion, absorption kinetics and subsequent muscle protein synthesis rates were measured during sleep.
It was found that in those individuals given casein protein, muscle protein synthesis occured and improvements were seen in overnight whole body protein balance.This study lends support to the fact that older individuals can preserve and gain muscle mass and that protein into the evening hours may help support these efforts.
A healthy Lean Body Mass (by encouraging muscle synthesis and growth) is necessary to promote an ideal body composition. As discussed above, evening protein intake may be beneficial in an older population specifically. The loss of skeletal muscle mass is, of course, a concern in maintaining health body composition, at any age.
Although we must not discount the effects of exercise (which will be further discussed), protein intake in the evening appears to be helpful in combating muscle loss and therefore beneficial for individuals looking to improve their body composition, at any age.
What about Obesity?
When looking also at individuals with certain health conditions, intake of certain nutrients into the evening may also be of benefit. Once again, whey protein, casein protein, and carbohydrates offer benefits when consumed into the evening hours. It has been shown that in those with obesity, whey protein, casein protein and carbohydrate consumed in the evening, have shown a positive effect on appetite scores.
Forty-four sedentary overweight and obese women were included in this study, in which they ingested either whey protein, casein protein or carbohydrates. Although there did not appear to be significant variations between each type of nutrient ingested, the next morning effects were seen on increased satiety and reduced desire to eat across all groups. The importance here is that increased satiety should assist with a lower caloric intake the next morning.
Satiety or the feeling of being full, is beneficial for healthy food selection choices and choosing smaller portions. A small evening intake of whey protein, casein protein or carbohydrate may offer some benefit. Perhaps a protein shake or nutrient-dense protein bar in the evening, a small piece of cheese with a few whole-wheat crackers or yogurt with granola and berries may be some healthy choices to consider.
A key here is small – remember, calories in versus calories out is an essential part of weight maintenance and therefore body composition.
Exercise can Help!
What if these effects are combined with exercise? In a study looking at the effects of nighttime feeding of carbohydrates or protein combined with exercise training, not surprisingly, all groups were shown to have an increase in lean mass and strength while reducing overall weight. Proof that exercise is a key component of healthy weight maintenance.
However, interestingly as well, when casein protein intake was combined with exercise training, morning satiety (or being full) was improved, which is again, beneficial of course for calorie intake.
Muscle Mass and Exercise Recovery
Looking specifically at muscle mass, the intake of certain nutrients into the evening is of benefit. Protein intake is essential in muscle formation and muscle recovery following exercise. There is evidence that protein ingested before sleep helps to stimulate muscle protein synthesis. In this study, ingested proteins were shown to cause a rise in circulating amino acid levels, increased whole-body protein synthesis rates and improved net protein balance.
This has significant implications following exercise and its effect on the preservation or improvement of lean muscle mass.
Following exercise, your muscles must be able to properly recover and protein intake is essential. Evening intake of protein appears to offer benefits beyond just satiety, but has direct effects on muscle protein synthesis and therefore muscle formation.
To achieve your weight management goals, you must achieve a healthy amount of Lean Body Mass. As Lean Body Mass is based on Skeletal Muscle Mass, protein intake is essential!
Not all night-time eating is bad for you!
Although at first thought, eating into the evening immediately brings to mind unhealthy habits. This does not hold true in all cases, however, when feeding with the appropriate foods. Although it is true that large, high calorie mixed meals before sleep may be detrimental for weight management and may have detrimental effects relating to obesity, not all eating before sleep is bad for you.
Small nutrient dense foods or specific nutrients offer benefits including protein synthesis and muscle maintenance, improved metabolism and increased satiety. The consumption of proteins, including whey protein and casein protein, along with carbohydrates, offer benefits for individuals of all ages when consumed into the evening hours.
For those who are active and exercising, these benefits may be amplified:
- Remember, not all night-time eating is bad for you.
- Consider your portion size and the type of nutrients you are ingesting.
- Small nutrient dense foods and specific nutrients such as whey protein, casein protein, and carbohydrates have been shown to offer benefits for weight maintenance!
- Don’t forget the effects of exercise: A healthy snack in the evening may support muscle growth and recovery, which is essential for Lean Body Mass.
Keep in mind that it is not suggested to take in all of your calories at night, and eating into the evening is not designed to offer you a 4th meal of the day. It is better to think of eating into the evening as a way to supplement your current healthy eating habits. It is always important to keep in mind your total calorie intake versus expenditure and this balance is essential for weight maintenance.
Night-time eating, if performed correctly, can have positive implications for overall body composition.
Dr. Jennifer Malowney is a practicing chiropractor, with an interest in preventative health. Her knowledge and clinical experience in the areas of health, fitness, and nutrition offer readers an informed and well-researched perspective.