Nutrition is a topic full of contradictions. There is a lot of misinformation, fad diets that promise quick fixes, retracted studies that are still circulating the internet, studies funded by companies that might just be constructed in a way to bias the results, and of course a lot of subjective opinions. You literally have to sift through all this information and look at the latest studies (and who they were sponsored by!).
The question of meal timing and meal frequency is definitely a topic in nutrition that has its fair share of contradictions. How many meals a day should we have? Is the traditional 3 meal a day the right way to eat or should we be eating smaller meals and more often? And what about intermittent fasting?
Firstly we have to take into consideration bio-individuality – no one size fits all. Everyone is different and has their own health needs as well as their own lifestyle and routine. But bio-individuality still fits into a parameter of what is scientifically proven to be good for us and what isn’t.
The traditional three meals a day
Humans didn’t always eat three meals a day. The hunter gatherers ate when they found food and likely practiced intermittent fasting unintentionally. According to historians, breakfast has been around since ancient Egypt, Greece and Rome. The Romans were known to have breakfast and one large meal in the afternoon and whether they ate anything in between appears to be debatable. During the middle ages people had a good breakfast after chores and then another meal in the late afternoon after the days work. So contrary to certain beliefs, breakfast was not invented in modern times.
Eating a meal in the middle of the day became popular during the 17th and 18th centuries in certain parts of the world. It became more common to have the last meal of the day a bit later and therefore lunch filled the gap.
Different cultures have had different meal timings throughout history and still do. However, just because a way of eating is a custom doesn’t make it necessarily good for us. The main concern with modern traditional eating is that most people have their main meal in the evening. As the day progresses, our metabolism slows down and so does our blood sugar control. Eating a large meal in the evening can lead to digestive issues, which can hinder restful sleep, and lead to weight gain.
So if eating three meals a day works well for you, just remember to consume the bulk of your calories earlier on in the day.
What about six small meals a day?
Six small meals a day is recommended for anyone who has gastroparesis, a condition that interferes with normal digestion and resulting in food sitting in the stomach for too long.
This way of eating was once touted as a good diet for diabetics as it was thought to help with blood sugar stability and better appetite control, however, today the science tells us that the traditional three meal day, whilst ensuring a good breakfast and a very light dinner (and of course paying attention to food quality) has proven to be far more effective at improving blood sugar levels [4].
However, six small meals a day has been shown to be beneficial for athletes[1] and someone who trains intensely on a daily basis as it allows the body to have a steady flow of blood glucose and therefore constant energy. It is also thought by some that one can only absorb a certain amount of protein at a time and therefore eating small amounts of protein spaced over six meals will counteract this problem. This is actually a misperception, as the amount of protein that can be absorbed is unlimited.[2] Nevertheless, this way of eating is a good choice for athletes, but this is also due to the fact that athletes tend to pay attention to the quality of the food and calories in each meal.
The downside with six small meals a day is that if you are not eating the right amount of protein, carbohydrates and fat, you can actually increase hunger[3] ,which may increase our perceptions of food as reward, encouraging overeating, and can lead to the less disciplined making unhealthy food choices. It is also not the most sustainable way to eat for most.
What about intermittent fasting?
Well the majority us humans fast through the night for around 8 hours, but studies shows us that fasting for longer than this can be highly beneficial for our body. Some of these benefits are better insulin control[5], brain health[6] cellular repair[7], weight loss[8] , and longevity as well as others. The common interment fasting time involves fasting for 16 hours and eating in an 8 hour window or fasting for 14 hours and eating in a 10 hour window, the latter being slightly less beneficial than the first, but still proving to be effective. There are other ways to intermittent fast such as alternate day fasts where one eats a very low amount of calories on fasting days, but although studies have shown positive results, especially for weight loss, this type of eating is far from sustainable and does not necessarily lead to lifelong positive dietary changes.
Intermittent fasting is not generally recommended for someone who does intense daily training, nor for those with certain health conditions such as diabetes, anyone with hormonal imbalances, children under 18, pregnant and breast feeding women, anyone with an eating disorder, amongst others. It is also not common place to recommend intermittent fasting to anyone over 65, but recent studies[9] show that a 14 or 16 hour fast might be safe for healthy seniors and yield positive results. Remember fasting doesn’t mean you need to skip meals, it simply means that you eat during a specific time.
When it comes to intermittent fasting, there is also the question of what are the best hours to abstain from food. Studies[10] show that breakfast eaters have lower rates of heart disease and high blood pressure. We also know that breakfast eaters tend to have more balanced blood glucose which is an important marker when it comes diabetes. What’s more, if you eat a good portion of a healthy breakfast which includes protein, good fat and fibre, you are much more likely to have better satiety, keep your hunger hormones at bay till lunch time and make healthier choices for your lunch time meal.
Moreover, as previously mentioned, our blood sugar control and metabolism are better in the morning than they are in the evening, so having a bigger breakfast is a far better choice than having a big dinner. Therefore, for those who like to fast for 16 hours, it would be best to have your last meal by 5pm or at least 6pm and your breakfast at 9am or 10am[11], as studies show. And even if intermittent fasting is not for you, your last meal of the day is much better off being a light easily digestible meal. If you really must have something before bedtime opt for a winter fruit or a few walnuts as these both help to promote restful sleep. There is a lot of truth in the saying eat breakfast like a king, lunch like a prince and dinner like a pauper.
Whatever your meal timings are and how ever frequent you eat, be sure to be mindful about the quality of the food you are eating. Every meal should be an opportunity to provide your body with good nutrition and not empty calories.
Source
6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8470960/
9. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9143805/
11. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4863265/