It appears as though periodized dieting may be better than continuous dieting for weight loss and maintenance.
A study published on September 17th found that men who went through a 2-week period of calorie restriction, followed by a 2-week period of ad libitum eating (or eating as they pleased), lost more weight than men who followed a continuous calorie restricted diet (CRD).
At the end of 16-weeks, those following the intermittent energy restricted diet (IRD) of 2-weeks on and 2-weeks off lost around 2 pounds more than those following the CRD. Average weight loss over that time period for both groups was around 14 pounds (6.36 kg). Researchers followed up with participants 6 months after the conclusion of the study, and found that IRD participants stayed an average of 8.1kg lighter than their CRD counterparts.
Both groups regained weight, but the IRD group kept more off.
Why do the researchers think this works?
Your resting energy expenditure (REE) is determined by body weight and body composition (fat vs lean mass).
As you lose weight, your REE decreases with it.
It’s been known that during weight loss efforts, REE decreases disproportionately to weight loss, leading to stalled efforts and eventual weight regain (what people call starvation mode).
This is thought to be your body’s preparation in response to decreased food intake in order to conserve energy so that you can make it through a famine period. I previously discussed feast, famine, and starvation mode here.
Researchers set out with the theory that the IRD would mitigate negative adaptive thermogenesis (the decline in calories burned in response to dieting). To see if they could counter this effect, participants were divided into two groups.
All participants decreased calorie intake to 67% of maintenance (a 33% reduction) as determined by a Resting Direct Calorimetry Assessment.
All participants ate the following diet, designed by a dietician, and supplied by a commercial kitchen, with occasional discretionary foods.
- 25-30% calories from fat
- 15-20% calories from protein
- 50-60% calories from carbohydrates
Participants in the IRD group followed this diet for 2-weeks, followed by 2-weeks of eating what they wanted, while the CRD group followed this diet for the 16-week duration.
As mentioned, both groups lost an average of 14 pounds over the course of 16 weeks, but the IRD group maintained a greater percentage of that loss 6 months later.
Researchers also found that the IRD group burned 377 kj/day more, roughly 90 calories, than the CRD group.
The authors also took time to point out that intermittent fasting is just as good as the intermittent energy restriction approach, but definitely not better. You can find more about intermittent and extended duration fasting here.
I happen to be a huge fan of intermittent fasting, but I’ll let the research and my previous post on fasting speak for itself.
What Should I Take Away From This?
- You may reduce the effects of metabolic decline by periodizing your dieting to 2-weeks on and 2-weeks off.
- You may lose more weight, and maintain that weight loss longer, by periodizing your dieting to 2-weeks on and 2-weeks off.
What Should I Do?
So you’ve tried everything. If you’ve read my posts, you may know my response. If you haven’t, then here goes.
Try it. Your body is your science laboratory. Everyones body is different. What may work well for others may not work well for you.
Participants in the study followed this approach for 16 weeks. If you follow it for 8, and don’t notice weight loss, then maybe the approach isn’t for you.
Don’t be the person who puts this off just because it seems to hard.
Either you can’t, or you won’t.
Just do it.
Lastly, I’m not a doctor. This is not medical advice. I’m just a nerd who likes to read research, and I figured I’d be productive by sharing it with you.
I’m a nerd, I know.
I read it so you don’t have to.
ps. If there’s anything you’re curious about, and don’t have the time, patience, or know-how to learn about it, let me know. I’ll be sure to post on it if it’s worth-while, or I’ll answer you directly!
- N M Byrne, A Sainsbury, N A King, A P Hills, R E Wood. Intermittent energy restriction improves weight loss efficiency in obese men—The MATADOR study. International Journal of Obesity, 2017; DOI: 10.1038/ijo.2017.206
- University of Tasmania. “Taking a break from dieting may improve weight loss: Research showed in a randomized controlled trial, that taking a 2-week break during dieting may improve weight loss.” ScienceDaily. ScienceDaily, 18 September 2017. <www.sciencedaily.com/releases/2017/09/170918222235.htm>.
Images courtesy of Pixabay, Public Domain Pictures, Tookapic