The famous saying goes “you are what you eat”, but in light of recent research, it appears that there may be more to this statement. Instead, it turns out that when you eat may be equally important as what you eat. Scientists recently found that regular eating times and extending the daily fasting period may reverse the negative health effects of a high fat diet and prevent conditions such as diabetes, obesity and liver disease. There is only one small problem!
At the moment this study has only been conducted on mice. However, this is an important study because it demonstrates that by simply controlling when food is consumed, instead of reducing the average daily caloric intake, the adverse health effects of a high fat diet were prevented. As with many studies done on mice first, it is a starting point for what is likely to be a topic of great interest and hopefully soon to be done with human subjects as well.
I will try not to get too scientific, but I just want to try and give you a quick overview of the study. The study looked at two groups of mice that shared the same genes, gender and age, and fed them a diet high in fat. The one group was allowed to eat whenever they wanted throughout the day, and the other group was only allowed to eat during an 8-hour period, and had to fast for the remaining 16 hours of the day.
They found that after 100 days, the group of mice who ate a diet high in fat throughout the day gained weight and developed high cholesterol, high blood glucose, and liver damage. The mice who were restricted to eating only during an 8-hour period weighed less than the other group, and had no adverse health effects despite consuming the same amount of calories from the same fatty foods.
The time-restricted mice also performed better when given an exercise test. The images below are of liver tissue from a mouse from each group, which shows the difference in fat accumulation (the white spots) between the two groups. The mouse who was allowed to eat 24 hours a day (left) had much higher levels of liver fat, than the mouse who was restricted to an 8-hour daily feeding period (right).
Mouse liver cells
The results are rather surprising, as for years we have been told to cut down on total calories, eat less fat, and have smaller meals and snacks throughout the day. What this study shows us, is that it may not only be the total amount of calories consumed that is the important factor, but it now seems that staying fasted for a longer period during the day may also help reduce, and in some cases prevent, certain health conditions like high blood pressure, high cholesterol, and type 2 diabetes.
So how does this work? It appears that when we eat the body stores fat and only starts to burn fat and breakdown cholesterol after a few hours of fasting. When we eat frequently, the study found that the body continues to make and store fat, expanding fat cells and liver cells, which can lead to liver damage. They found that during a fasting period, the body turns on fat burning mechanisms and cuts down fat storage, reducing overall body fat and keeping liver cells healthy.
Although this study has seen positive results in mice, the main question is what these findings mean for humans. We should not jump to the conclusion that eating lots of unhealthy foods is alright as long as we eat them within a certain time period. Instead, the main take-home message is that even though eating at regular times during the day and overnight fasting has been seen to be beneficial in mice, we will still have to wait for human studies to prove this. If this is found to be proven in humans, this could be a new drug-free and relatively simple lifestyle modification to prevent obesity and diabetes.