This article was originaly published as an op-ed in The Jerusalem Post (19 Dec. 2024): https://www.jpost.com/opinion/article-834012
In the world of weight loss and health, the next fad is always just around the corner. If you’ve been around long enough, you’ve seen hundreds of strange diets, like eating only grapefruits or just eating cabbage soup. Yes, people lost weight on those diets, but then the weight probably came back with some extra pounds. Maybe you remember the use of amphetamines to lose weight. One woman told me her doctor prescribed them to her. She said she did lose weight… and also got 3 hours of house work done in about an hour! That weight didn’t stay off either. People were very disappointed when the popular, effective drug fen-phen was discontinued. Its biggest issue was that it could kill you.
What about interventions that do not solely rely on food, medications or supplements, and supposedly even elicit good results? I know of someone who lost a lot of weight without any radical changes to his diet. He simply stopped eating every evening at about 6:30 and resumed his eating about 8:30 the following morning. This person engaged in a type of intermittent fasting.
What is this type of fasting and does it really have a lasting, positive effect?
Time Restricted Eating
Professionally, we call this Time Restricted Eating or TRE. It comes in a range of versions. One version is 8 hours of eating solid food and 16 hours of only water, tea and black coffee. Another is 5 days a week of regular eating and 2 days where you eat 6 hours and fast 18. There are many variations in between. Does it work and if so, why?
There is no shortage of studies, many of them positive, about the effects of eating less hours in the day. Some of these studies show improved weight loss, reduced type 2 diabetes, better brain health, and reduced inflammation and oxidative stress. All positive.
A new study that came out this past September tells a different story. As stated in the study:
- A study of over 20,000 adults found that those who followed an 8-hour time-restricted eating schedule, a type of intermittent fasting, had a 91% higher risk of death from cardiovascular disease.
- People with heart disease or cancer also had an increased risk of cardiovascular death.
- Compared with a standard schedule of eating across 12-16 hours per day, limiting food intake to less than 8 hours per day was not associated with living longer.
That certainly turns much of the previous research on its head!
A study published in The Lancet this past September showed people doing TRE for 3 months had very little health benefit or weight loss. To be clear, a lot of the early research was taken from animal research and not humans. It may be that now, with more human-focused studies, we will get a more accurate picture.
Diet quality
One of the single most important variables has to do with diet quality. Does a person who fasts on a poor-quality diet, or one containing more fat, do as well as a faster following a whole-foods and plant-predominant diet? Most experts agree that diet quality is still more important than when one eats.
What if I combine a high-quality diet and some version of time restricted eating? That is what we do at The Wellness Clinic. First, we adjust the diet to be majority plant-based. We make sure clients are getting enough water and adequate sleep. We also encourage exercise. Nevertheless, we also try to do is to be sure there is a 12-hour time period, in coordination with sleep, where clients don’t eat solid food. There is good science behind the 12 hours. Yes, there will be occasions (like the Passover Seder or a late wedding) where you just will have to eat late. Still, as long as we have this break most of the time, it is effective. Why does this work?
What happens during these breaks?
Two main things tend to happen during breaks. One, people just end up eating less calories. All of the extra calories one may have consumed noshing in the evening are gone. However, that is not the main effect. That 12-hour fast is great for your gut microbiome. It is one of our tools to encourage more anti-inflammatory microbiota and less inflammation. We are all looking for this outcome.
Combining a gut-positive diet with this gut-favorable abstinence from eating for 12 hours is a great combination. It will help you lose weight, and by achieving positive gut-health, will help your general health and well-being. Another important side-benefit? A better night’s sleep.
It’s never one thing alone with regard to positive health results. When we combine what the science tells us from different disciplines, we can have amazing results and wonderful health outcomes. How many steps you take daily, how many fruits and vegetables you eat, or when you stop eating are all important actions. Yes, there are some contradictory studies and evidence about time restricted eating. But it does seem that not eating solid food, most nights, for 12 hours, has value. Combine that with a high quality plant-based diet, exercise and all of the other wonderful aspects of lifestyle medicine, and this will go a long way toward “adding hours to your days, days to your years and years to your lives.”
GREAT!