Does time-restricted eating work for weight loss? Well, as is the case with most diets and ways of eating, it depends. A recent paper found time-restricted eating(TRE) provided no benefit to weight loss over standard calorie restriction.
As is the standard social media protocol, half the people freaked out and half said I told you so. But all the hub-bub over these findings is a bit odd. It really doesn’t tell us anything new. In fact, based on the other data, this is exactly what we’d expect.
In today’s video blog, we chat about this study and compare the findings to other studies in the TRE space.
Does time-restricted eating improve weight loss over calorie restriction?
Many people feel there’s a preponderance of evidence that TRE leads to weight loss whether you are in a caloric deficit or not. I’m sure this is not at all related to the way it’s framed in popular diet books and blog posts.
There does seem to be evidence that TRE may improve certain cardiometabolic risk factors in humans, even without weight loss. But there’s none showing weight loss independent of calorie intake.
This new study looked at 139 obese Chinese people and divided them into 2 groups, both were calorie restricted. One group followed TRE from 8am-4pm while the other group ate whenever they wanted. Important point: Even the non-TRE group ate in a less than 12-hour window.
Results of the paper showed that TRE w/ calorie restriction showed no significant difference in weight loss compared to calorie restriction alone. There was also no difference in cardiometabolic risk factors between the groups.
Does this jibe with the other TRE data?
Many people disagree with the findings of this study, and feel it’s at odds with other human data. From a weight loss perspective, it’s perfectly in line with the other data. Weight loss requires caloric restriction, and weight loss is generally in line with the level of caloric restriction.
One thing that doesn’t jibe with the other data at first glance is no change in cardiometabolic risk factors(A1c, TGs, etc.). But there’s actually an explanation for this: These people habitually followed TRE before the study anyway.
The baseline eating window was just over 10 hours, which qualifies for TRE. Despite their natural inclination to follow TRE before the study, they still managed to become obese because they were overeating.
So that upholds the idea that calorie restriction is necessary and TRE didn’t really add any weight loss benefit. Though there was a small, insignificant increase in weight loss in the TRE group, they also ate fewer calories(> than 100cals/day at months 6 & 12). This further supports the idea that it’s the calorie restriction causing the weight loss.
But, it would make sense to see no difference in cardiometabolic risk factors because they were all following some form of TRE anyway.
It can all seem a little confusing, but this really isn’t a surprising result. If you’d like a full accounting of what the study shows, as well as other data in humans, and how you can make TRE fit into your life, check out today’s video below:
(5:08) Findings of the TRE+CR vs CR alone study
(11:00) Other data (TRE improves metabolism)
(14:12) Other data (TRE & hormonal synchronization)
(20:09) TRE improves metabolic syndrome
(22:04) Making TRE work for you
(28:38) Takehome from this paper(& others)
This study upholds the idea that, if weight loss is your goal, calorie restriction is your gal, or dude. You can do that any number of ways, and time-restricted eating is a valid tool for weight loss.
But time-restricted eating doesn’t independently lead to weight loss without calorie restriction, which no one should really think anyway. Any tool that changes your eating behaviors and causes you to eat less is great! This is how all ways of eating work for weight loss.
Some believe that since both groups were essentially doing TRE anyway, that these results aren’t indicative of the effect of TRE. But, they were doing TRE before the study, and still somehow managed to become obese, which further supports the idea that calorie restriction is what drives weight loss in people doing TRE.
The finding that there was no difference in cardiometabolic risk factors is at odds with the other studies on TRE. But, since both were already doing TRE anyway, you wouldn’t expect to see a change. Personally, the cardiometabolic effects are why I do TRE.
This shouldn’t dissuade you from trying TRE. In fact, take some of the tips in the video for a test ride and see how TRE works for you. If it spontaneously leads to weight loss by causing you to restrict calories, is that a bad thing?