When to Eat
Whilst we know that what we eat and how much we eat both affect weight and health it may not be quite so obvious that when we eat also has an impact.
Many studies emphasise that the timing of food intake, as well as what is eaten, may have a significant role in weight gain and associated problems. For example studies show that dieters wanting to lose weight who eat a high calorie breakfast will experience significantly greater weight loss than those who eat a high calorie evening meal regardless of how many calories are eaten in the course of the day (1).
Information from over 50 000 participants in the Adventist Health Study found that there were 2 factors associated with a higher Body Mass Index (BMI):
1. Eating more than 3 meals a day. Snacks are counted as extra meals.
2. Making the evening meal the largest meal of the day (2).
One interesting discovery that is relevant here is the presence of an active circadian clock in different organs related to food intake including the stomach, intestines, pancreas and liver.
Adipose (fat) tissue in the body also has a daily rhythm that controls whether fat is accumulated or mobilised. Given that the food we eat is the source of energy for adipose tissue, the time of feeding, particularly for high-energy content meals, is likely to have an effect on what the adipose tissue does with the calories (1).
Being a Lark or an Owl could make a difference
Evening types, or owls, tend to have a preference for doing more of their daily activities later in the day including eating more calories in the evening, thus increasing their risk of weight gain compared with morning types. That said, if morning types eat most of their calories in the evening they too will increase their risk of obesity and associated problems (3).
Meal Timing and COVID-19
COVID-19 and metabolic syndrome are both sweeping the globe, Effective control of the parameters that lead to metabolic syndrome may help minimize the effects of SARS-CoV-2 by reducing the inflammatory response and blocking the entry of the virus into cells.
Data has been gathered from dietary surveys conducted in nine European countries to explore the relationship between the time of the evening meal and death rate due to COVID-19 infection. The timing of the evening meal varies between 16:00 and 21:00 across the countries sampled. A strong correlation was found between the time of the evening meal and death rate. The study findings indicate that the later the time of the evening meal, the higher the death rate and vice versa (4).
In short, eating a large meal in the late evening appears to be a risk factor for obesity, metabolic syndrome, type 2 diabetes, and death from COVID-19 infection.
Interestingly, this research confirms an oft quoted nutritional maxim: Breakfast like a king, lunch like a prince and eat dinner like a pauper.
1. Physiol Behav. 2014 Jul;134:44-50. Timing of food intake and obesity: a novel association. Garaulet M et al.
2. Kahleova H, Lloren JI, Mashchak A et al. Meal Frequency and Timing Are Associated with Changes in Body Mass Index in Adventist Health Study 2. The Journal of Nutrition, 2017; jn244749
Chronobiol Int. 2019 Jan;36(1):27-41. Chronotype and energy intake timing in relation to changes in anthropometrics: a 7-year follow-up study in adults. Maukonen M et al.
Chronobiol Int. 2020 Jun;37(6):804-808. Early dinner or “dinner like a pauper”: Evidence, the habitual time of the largest meal of the day – dinner – is predisposing to severe COVID-19 outcome – death. Verd S et al.