No, we're not joking. Recent research has revealed the very exciting possibility that taking a break from your diet -- or having a "diet holiday" -- may not actually impede your weight loss efforts, but actually improve them.
Conducted in mice (though with human clinical trials currently underway) by researchers from the University of Sydney and Garvan Institute of Medical Research, the research suggests taking a break from continuous dieting actually improves the efficiency of weight loss, rather than the other way around.
Better yet, existing research suggests that this phenomenon will also apply in humans, and could potentially redefine the way in which we approach losing weight.
Lead author, Associate Professor Amanda Salis, says it's a subject that has long been close to her heart as she herself has struggled to lose weight over the years.
"The issue of weight loss has always been a frustration of mine because I did, in the past, have a lot of excess weight," Salis told The Huffington Post Australia.
"I was severely obese, and part of my frustration to lose weight was that all the diets were about eating less and moving more and to keep it ongoing until you got where you wanted to be.
"But I couldn’t get anywhere. I would get so ravenously hungry. I would stay on a particular diet for two weeks and lose a little bit of weight, but I couldn't stick to anything long enough to get anywhere."
Her personal struggles got Salis thinking about the issue in a scientific frame of mind, which in turn, prompted her to embark on what she calls "a little self-experiment."
"I started taking breaks from losing weight, based on a theory on how our bodies respond to weight loss," Salis said. "So when we do start losing weight -- and everyone can lose weight for little while -- the body responds with a famine reaction.
"The weight loss causes chemical reaction to the part of the brain that controls hunger, and makes you very hungry as well as crave rich, fattening foods. When your body is reacting in this way, it's extremely hard to stick to a diet."
Salis' reasoning was, if she gave her body a break from her diet, she would therefore prevent the "famine reaction" from kicking in, because her body would understand it wasn't starving. Lo and behold, it worked. Salis lost 30 kilograms.
"But that’s just one person," Salis said. "Every person has their own way of losing weight. I wanted to test this in a scientific way, hence the mice study."
So how did they do it?
Basically, the team had two groups of obese mice. Each group were effectively put on a healthy diet for the period of 12 weeks -- with one important difference.
The first diet was continuous, meaning the mice were fed 82 percent of their normal daily kilojoule intake for the duration of the study. (These were presumably the miserable mice dreaming of cheese and resenting their exercise wheel.)
The second diet also saw the mice have 82 percent of their normal kilojoule intake -- but for only five or six days at a time. For the next one to three days, the mice took a holiday from their diet and could eat as much as they wanted.
The result? Both groups of mice lost exactly the same amount of weight, despite the fact that the mice on the (undoubtedly more fun) intermittent diet ate 12 percent more during the course of the trial.
There was no difference in weight gain, fat mass, circulating glucose or insulin concentrations. Basically, the mice on the intermittent diet got more bang for their buck, weight-loss wise, while the mice on the continuous diet slugged it out for the same result.
"Twelve percent is a lot of food when you are dieting," Salis noted. "Being able to have something like an extra cheese and tomato toasted sandwich is actually quite a lot of food. And the benefit of that is it could be a more sustainable way to lose weight -- something to stick to in the long term. Because dieting is a long term thing. I mean, weight management is a long term thing."
In collaboration with Bond University, the University of Queensland, and Queensland University of Technology, Salis' team is currently conducting clinical trials with human subjects to see if they reach the same result. The trials vary in lengths, with a minimum of 12 months.
For Salis personally, the "holiday diet" gave her a sense of control and purpose she was unable to maintain on any of the other diets she experimented with.
"Instead of feeling like I was weak and failing on the diet and not very good at the diet, I was more thinking, 'yes, this is food. I’m deactivating my famine reaction.' I felt completely in control,' Salis said.
"It completely changed the process for me and I struggled for six years before that. I felt like it put me in the drivers’ seat, and from then on I either lost weight or was keeping it off. It was the most wonderful thing."
If the clinical trials prove successful, Salis hopes the new research will change the way we currently view the process of weight loss and dieting.
"I'd like to see 'diet holidays' incorporated into weight loss programs, so instead of trying to stick to a diet continuously, you actually engineer those proper breaks into the program so that your body can have a rest and the chemical changes causing difficulty with hunger control can be normalised," Salis said. "Then you can go back on the diet."
Of course, it's worth pointing out your 'holiday diet' doesn't give you an excuse to binge on Macca's and ice cream. It's about eating as much good, healthy food as you like, and satisfying your body when it tells you it is hungry.
"We're talking about a diet based on fruits and vegetables and wholesome carbohydrates and lean meat and protein sources and dairy," Silas said. "Though it doesn’t mean there isn't a place in every diet for discretionary foods like ice cream and chocolate, as long as they are within proportion. A small amount is not a problem."
To participate in Associate Professor Amanda Salis’ clinical weight loss trials at the University of Sydney, head here to register your interest.
To participate in the team’s clinical weight loss trials at Bond University, head here.
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