Eran Segal , co-author of the research said, "It's generally known diets fail and don't work. One of the novel aspects we examined here is the phenomenon of relapsing obesity.
It's typically not because diets don't work initially, the problem is the weight regain. People go on diets over and over again, and keep failing on that."
‘Flavonoids are natural compounds found in fruits, vegetables encourage cells to burn fat rather than storing it in the body.’
While our body loses weight, the microbes living inside us used to a fatty diet remain for many months. And when they come across fatty foods again, they go into overdrive, making us pile on the pounds at an accelerated rate.
Researchers believe the bad gut bacteria cause a fluctuating weight by destroy natural compounds found in our food that encourage us to burn fat.
This effect could be reversed, scientists believe, by taking a drink containing high levels of the substances which our found naturally in fruit and vegetables.
These compounds - flavonoids - encourage our cells to burn fat rather than storing it.
One of the flavonoid compounds, apigenin found in parsley, celery, celeriac, and chamomile tea. The other, naringenin, is present in grapefruit, oranges, tomato skin and water mint.
The new study carried out by Israeli researchers investigated how mice who became obese after a high fat diet, successfully lost weight after a normal diet.
But when they started eating fatty foods again, they regained at an accelerated rate.
This made them even heavier than they were before, and heavier than mice who stayed on a high fat diet the whole time.
And when the fat mice's community of gut bacteria was transferred to normal mice, these normal weight mice also showed accelerated weight gain when eating fatty food.
Key to the process was bad bacteria in the gut reducing the levels of flavonoids in the gut, the scientists said.
As the flow of these chemicals into the body was cut off, more fat was stored, and less burnt off to create warmth.
The yo-yo diet also increased glucose intolerance, a sign of increased risk of type two diabetes to a greater effect than in mice who stayed on a fatty diet continuously.
Tests to find what caused the weight gain found two flavonoid compounds, apigenin and naringenin were much lower in the yo-yo-ing mice than in normal mice.
Feeding the mice drink with very high levels of the flavonoids- more than can be absorbed by the gut bacteria helped to curb post-dieting weight regain in mice.
Eran Segal , co-author of the research said further research is needed before the same process works in humans.
He added, "although the study was on mice we believe that a similar phenomenon in humans would also persist."