“A downside to fasting”, Intermittent fasting doesn’t work…”, “A potential downfall to fasting”.
These headlines dominated health and nutrition channels this week. As with most all “news” or headline worthy content these days, their thoughtfulness typically ends at the title.
The study, “Effects of Time-Restricted Eating on Weight Loss and Other Metabolic Parameters in Women and Men With Overweight and Obesity – The TREAT Randomized Clinical Trial“, is a welcomed study as it’s a Randomized Controlled Trial (RCT), something you don’t see often in nutrition.
Next, let’s address the elephant in the room – yes, I wrote a guide on Intermittent Fasting in 2018. To this day I still utilize it personally, with clients, and continue to read up on it as I expect science to evolve over time. However, I don’t use it with everyone and don’t believe it offers magical benefits that cannot be achieved via alternate means.
The Study
- 116 overweight or obese individuals
- 12 weeks
- Patients between 18-64 with a BMI between 27-43
- Patients randomized between:
- CMT – Consistent Meal Timing (3 meals per day)
- TRE – Time Restricted Eating (eating only between 12-8pm)
The Findings
Both groups ended up losing weight TRE (.94kg) and CMT (.68kg). One of their “secondary endpoints”, which should be met with some caution (more later), was that TRE lost more lean mass (muscle) than CMT.
The authors conclude, “TRE did not lead to a statistically significant difference in weight loss at 12 weeks”.
Now the Fun Part
As Jordan Peterson once said, “almost all ideas are wrong…it is your job as a critical thinker to attack that idea with everything in your arsenal and see how it holds up.” So I shall.
First, there was zero attempt to control calories or influence macro-nutrients. The fasting group was told to, “eat ad libitum”, which means until full. Otherwise, people were basically told to just eat and drink whatever they want (not something you’d likely tell someone who is beginning a weight loss plan).
Both groups ate 3 meals as per instruction. However, people who fast, typically reduce their overall meals to 2 by skipping breakfast. We know that weight loss occurs from a sustained calorie deficit. I think a more pertinent question would be, “does time restricted feeding make it easier to adhere to a calorie deficit?”
Second, the study used self-reports to measure compliance. It appears as though 92% complied with CMT and around 82% complied with TRE. Non-compliance wasn’t defined well and we have to consider how often participants misreport things.
If you use the data of those who complied, the TRE group lost 1.16kg and CMT lost .74, which is a larger discrepancy than the overall findings.
Third, intermittent fasting isn’t solely studied for weight loss,. There are other health parameters that would be useful in studying.
Another attention-grabbing headline was the TRE group losing more lean mass than the CMT group. However, there appeared to be a difference in exercise (step count) between the two groups and again, there was no guidance on protein, calories, etc.
My Thoughts
This study is still a great addition to all of the research we have on weight loss. However, I’m not sure how much useful information I can extract from it given my specific clientele and the absence of resistance training and education on calories/macro-nutrients. This study is likely helpful for the quacks who believe that a specific window of eating is all-mighty and powerful, regardless of what you eat.
I have ALWAYS maintained that there is no best diet plan. Instead, we need to find out how to structure an individuals diet to positively influence long-term adherence and allow them to reach their goals. Personally, I have found periods of fasting to help me reduce appetite, and thus lower my overall calories (helping me hit my goals). I am also interested in longer fasts and their ability to up-regulate autophagy, which could have significant health benefits.
So, how might we offset the slight reduction in lean mass? Quite easy. Add resistance training (which results in a net anabolic response further promoting the addition of muscle mass or at least maintenance) and increase protein intake. The participants were overweight/obese people, which nothing against them, but their knowledge of appropriate protein intake is often lacking.
How about the other health parameters? Most of the research that looks into longevity and IF are investigating much longer fasts, 20+ hours. This was a relatively small TRE plan of 16:8 (fast to eating).
Closing Thought
Once you establish a goal, determine the best feeding schedule for YOU. Fit your diet into your life, don’t fit your life into your diet.
For additional information on Fasting you can read my Previous articles, my book Feast.Fast.Fit., or examine some of the studies below.
Leave a Reply