Fitness Myth: Late Night Eating Makes You Gain Weight
Eating late at night does not impact your weight any differently than during the day so why have we been constantly told by trainers, friends and even nutritionists that indulging in some ice cream before bed or going out for that late night dinner will cause us to pile the pounds on? Nutritional science is getting better year after year, expanding the boundaries of knowledge and brining new technology into our lives. But, as in other sciences, in nutrition there are old ideas that need to simply disappear, the idea that the calories you eat after 7pm or late at night will be automatically turned into fat is one idea that needs to die.
The Origins
In the 1970’s Adelle Davis, an author and nutritionist, gained mainstream media attention (think of Dr. Oz today) were she advocated for things such as unprocessed food and vitamin supplementation. Davis popularized the idea that late night eating was bad with her phrase “eat breakfast like a king, lunch like a prince and dinner like a pauper”. Davis was scrutinized in the academic community for advocating for these things has she didn’t have the scientific backing to support her claims resulting in what at best could be claimed as half-truths. The myth of late night eating comes not from scientific studies but from a simple and logical argument. The argument goes a little like this, because you aren’t active during your eight hours of sleep and your metabolism naturally slows the food you eat late at night will be turned into fat as you lay asleep. This idea was supported initially by surveys done asking people if they eat late at night and what their weight/ height was, these surveys found that the people that reported eating or “snacking” late at night also had a higher number on the Body Mass Index (BMI).
The Science
Unfortunately for Davis’s theories scientific studies on late night eating, not just surveys, show that consuming calories late at night is no different than during the day for weight loss or gain. This is also the official stance of the U.S. Department of Agriculture’s Weight Control Information Network, they state that “it does not matter what time of day you eat. It is what and how much you eat and how much physical activity you do during the whole day that determines whether you gain, lose, or maintain your weight” . However the question remained, why where those surveyed who reported late night eating having a higher average BMI number. To begin it is well document that obese patients commonly under report their eating habits indairies and surveys, so scientific studies were needed to reveal why late night eaters were heavier others. The answer came when researchers watched what and how much food these people were eating late at night. The problem was revealed to be two fold, firstly late night snacks usually consist of high calorie food such as chips, ice cream and sweets. Secondly, late night eating often takes the form of binge eating were people can consume more than 25% of their daily calories.
Late night eating is rarely driven by hunger but instead driven by social environments or indulgence. When dining out to celebrate a win or a birthday we are faced with oversized portions and an almost obligatory wine/beer/liquor beverage which cumulates in a substantial intake of calories. At other times we indulge in things such as 1,100 calorie bags of buttered popcorn or a tub of ice cream during a quiet night in. The food choices popular for late night consumption are either high in fat, sodium, sugar or all three, this makes it all too easy to consume an excessively large amount of calories after a day full of regular meals. Eating these foods means that we often go to sleep having consumed sometimes 30% more of our daily calories without realizing it. For individuals that often consume upwards of 25% of their daily calories at night it is labeled as Night Eating Syndrome (NES). Consumption of such an excessive amount of these high caloric foods late at night is particularly troublesome as we go to bed often without the felling of fullness as these ‘junk’ foods often result in significantly lower levels of satiety or fullness. In healthy and obese people eating at night is simply the consumption of extra calories that aren’t needed, in one study of healthy young males eating at night represented a extra 600 calories (a) a day. To put this number in perspective when trying to lose weight you would want to reduce your daily caloric intake by about 600 calories to lose 1LB a week. It should be noted that night time eating has been shown not to affect your metabolism when training or losing weight 1 2 .
The Controversy
As everyone’s body is unique controversy will always be in nutrition, some studies of mice have shown that consuming high fat high sugar foods late at night triggers a different insulin response then during the day which might lead to weight gain. Moreover while there are several studies researching the effects of late night eating on obese patients there are few conducted on people in healthy weight ranges. This doesn’t mean we should doubt the total calorie theory but don’t be surprised if new research on patients comes out revealing that particular kinds of high sugar high fat foods might encourage weight gain.
Myth Debunked
Contrary to public opinion and those originating from an overzealous nutritionist/ author in the 1970’s consuming calories late at night is not different than during the day for weight loss or gain. The science has shown that there is no conclusive evidence indicating that consuming calories at night is different than during the day for fat loss. So go ahead and enjoy that piece of cake or stout beer in the evening just make sure you reduce your caloric intake by 250 calories for the following day to balance yourself out.
(a)Restricting night-time eating reduces daily energy intake in healthy young men: a short-term cross-over study by James D. LeCheminant, Ed Christenson, Bruce W. Bailey and Larry A. Tucker in the British Journal of Nutrition (2013), 110, 2108–2113.
