Does eating food after 8:00 p.m. induce more weight gain?

Marjet Heitzer, Ph.D. The Plateau-proof Diet Foundation. Http://www.plateauproofdiet.com The short answer to this question is- NO. Although this myth has been perpetuated for many years, it is a myth nonetheless. Because individuals are more likely to be sedentary (less active) later in the day, the myth states that you won't burn off the food eaten late at night. Hence because late night meals and snacks aren't immediately burned off, it is stored, hence weight gain. In this article, we will find out that consuming a meal or snack late in the evening has no additional consequences as eating a meal or snack in the morning in reference to weight gain. Rather, it is the total amount of food as well as the combination of macronutrients (protein, carbohydrate, or fat) (http://www.plateauproofdiet.com) consumed during a 24 hour period which is more important. So, what was the basis of this myth? After a great deal of searching, we discovered one very small study that included only 10 slightly to moderately obese women eating a controlled diet (provided by the study investigators). The authors of this study determined that there was a slight enhancement in weight loss when individuals consumed higher daily energy in the morning (breakfast and lunch) as opposed to the evening (dinner and evening snack) (1). In the first 6 weeks, the time of day in which most of the food was consumed did not matter. However, in the following 6 weeks, the investigators observed that women, who consumed most of their food energy in the morning hours, lost slightly more weight (8.6 and 7.2 lbs., respectively) than women who consumed more food in the evening. However, women that had the evening meal schedule lost less fat-free (or lean) mass, indicating that they had a greater loss of body fat percentage. It should be restated that the results indicated only a slight benefit from consuming most of their food in the morning. Also, because the number of participants in this study as well as the length of the study was very small, it is difficult to determine if this trend would continue. Although meal time does not directly affect weight gain, people that eat breakfast are less likely to be obese. There is some evidence that people who consume more food in the morning hours tend to consume less total food (2). A study by deCastro et al. observed 375 men and 492 women eating ad libitum (at their own discretion) using a diet journal system (2). They found that consuming food in the morning may provide more satiety (the feeling of fullness) as compared to eating food later in the day. This may be why meal sizes tend to increase and between meal intervals decrease as the day progresses, resulting in ingestion of approximately 150% more food energy in the evening as compared to the morning. So, people who tend to consume more food in the evening hours were inclined to consume more total food. It may be that eating breakfast and a larger lunch influences an individual's feeling of hunger, thereby influencing the amount of total food consumed in a day. Obese people tend to consume more food that normal sized people and most of that food is eaten in the evening (3). Although consuming food in the evening doesn't affect weight gain directly, if a person skips breakfast and consumes most of their food in the evening, they generally eat more, leading to increased weight gain. Alternatively, people who eat breakfast tend to consume less food totally throughout the day. It should be noted that this article is concerned with moderate evening meal and snack consumption and not excessive evening eating as in night eating syndrome (NES). NES is characterized by morning anorexia, evening hyperphagia (enormous overeating), as well as insomnia (4). Individuals suffering from NES are fully awake and conscious during these episodes. Most people with NES consume more that 50% of their daily caloric intake after their last evening meal in the form of evening snack (5). Although NES is often associated with obesity, it can be present in non-obese individual (6). Finally, NES is also associated with depression. If you think you may be suffering from NES, it is important to immediately contact your primary care physician to discuss relevant treatment options. 1. Keim NL, Van Loan MD, Horn WF, Barbieri TF, Mayclin PL 1997 Weight loss is greater with consumption of large morning meals and fat-free mass is preserved with large evening meals in women on a controlled weight reduction regimen. J Nutr 127:75-82 2. de Castro JM 2004 The time of day of food intake influences overall intake in humans. J Nutr 134:104-11 3. Berteus Forslund H, Lindroos AK, Sjostrom L, Lissner L 2002 Meal patterns and obesity in Swedish women-a simple instrument describing usual meal types, frequency and temporal distribution. Eur J Clin Nutr 56:740-7 4. Birketvedt GS, Florholmen J, Sundsfjord J, et al. 1999 Behavioral and neuroendocrine characteristics of the night-eating syndrome. Jama 282:657-63 5. Tanofsky-Kraff M, Yanovski SZ 2004 Eating disorder or disordered eating? Non-normative eating patterns in obese individuals. Obes Res 12:1361-6 6. Stunkard AJ, Allison KC 2003 Two forms of disordered eating in obesity: binge eating and night eating. Int J Obes Relat Metab Disord 27:1-12