Intermittent fasting (IF) is a technique of eating based on time. The idea is that fasting for long periods of time lowers insulin levels enough that our bodies will use fat for fuel. Growing evidence in animals and humans shows that this approach results in significant weight reduction. When combined with a nutritious, plant-based food plan and regular physical activity, IF may be a part of a healthy weight reduction or maintenance plan, as I described in an earlier blog post.
Now, A A randomized controlled trial Published in Jama Claims that IF has no significant weight reduction advantages and a big negative effect on muscle mass. News outlets picked up the story and ran headlines like this. Possible Disadvantages of Intermittent Fasting And An unintended side effect of intermittent fasting.
But what did this study actually have a look at and find?
In the study, 141 patients were randomly assigned for 12 weeks to either a time-restricted meal plan (TRE) that consisted of fasting for 16 hours and eating only during an eight-hour window through the day, or Constant time for dinner (CMT) was included. Meal plan, with three structured meals a day plus snacks.
Neither group received nutrition education or behavioral counseling, nor was physical activity really useful. There was no real control group (meaning a gaggle that received no instructions about meal times).
Interestingly, each groups lost weight. Looking on the headlines, I needed to read and re-read the outcomes several times, because they showed that the IF group lost statistically significant weight from start to complete—which was not true within the CMT group. The researchers reported: “There was a big weight reduction within the TRE group (−0.94 kg; 95% CI, −1.68 kg to −0.20 kg; P = .01) and a nonsignificant weight reduction within the CMT group (− 0.68 kg; 95% CI, −1.68 kg to −0.20 kg; P = .01). % CI, −1.41 kg to P = .07).
Translated into plain English, the IF group lost more weight than likelihood: half a pound and 4 kilos, or a mean of two kilos. The controlled-eating group also lost some weight, although the quantity lost could possibly be resulting from likelihood: between 0.1 and three kilos, or 1.5 kilos on average. The result was that there was no significant difference in weight change between the 2 groups. And the researchers observed a decrease in muscle mass within the IF group that didn't occur within the CMT group.
Dive deep into the study
By the best way, all these people could also be eating fried or fast foods, and sugary sodas and candy – we don't know. The study didn't measure food plan or physical activity. IF shouldn't try this! And yet IF people still lost between half a pound and 4 kilos.
Importantly, the controlled-eating group also lost weight. Although not significant enough to prove that this was resulting from the intervention, it was sufficient for some participants to make the load lack of the managed food plan barely different from the IF weight reduction. But give it some thought: structured eating is an intervention. After all, some people eat greater than thrice a day, eating multiple small meals throughout the day. Telling people to limit their eating to 3 meals and snacks may very well help some people eat less.
The authors could thoroughly conclude that IF was indeed successful. They may additionally call for a follow-up study with a real non-intervention control group in addition to behavioral counseling, guidance on healthy eating, and really useful activity levels for the IF and CMT groups.
Does extra support matter?
Early studies of IF which have provided behavioral counseling, and guidance on nutrition and activity, have actually shown positive results. For example, in a previous blog post I discussed 2020. American Journal of Clinical Nutrition the study through which 250 obese or obese adults followed certainly one of three diets for 12 months:
- On the IF 5:2 protocol, which suggests drastically reducing food intake (as much as 500 calories for ladies and 700 calories for men) on any two of the five days of the week.
- Mediterranean, with an emphasis on vegatables and fruits, beans, nuts, seeds, whole grains, and olive oil sparsely Fish, chicken, eggs, and dairy, and one glass of wine per day for ladies and with allowance in two days for men.
- Paleo, which emphasized vegatables and fruits, animal protein, coconut products, butter, and olive oil, in addition to some nuts, seeds, and legumes.
- And this is essential: All participants were educated on behavioral strategies for weight reduction, stress management, sleep and exercise.
Everyone lost weight. The IF group lost a mean of 8.8 kilos, followed by Mediterranean at 6.2 kilos, and paleo with a mean of 4 kilos. Adherence to the Paleo food plan (35%) was higher than the Mediterranean food plan (57%) and IF (54%), and higher adherence resulted in a single to 3 kilos more weight reduction. The Mediterranean and IF groups also saw significant reductions in blood pressure, one other good result.
What concerning the lack of muscle mass within the IF group? Jama Although this study needs further study, it will be significant to notice. Other research on IF involved physical activity guidance. No lack of muscle mass was shown.
The bottom line
What's the takeaway here? A high-quality food plan and adequate physical activity – including resistance training – are vital to our good health, and there isn't any substitute for these recommendations. IF is solely a tool, an approach that may be quite effective for some people to reduce weight. Although this one negative study adds to the body of literature on IF, it doesn't reverse it. We just need more high-quality studies to achieve a greater understanding of the best way to most effectively incorporate IF right into a healthy lifestyle.