Eating as much as you want one day and fasting the next is one of the quickest ways to lose weight, research finds.
Alternate-day fasting not only helps people lose weight, but also improves their health and reduces the risk of disease.
People in one study who fasted on alternate days lost 8 pounds in four weeks.
Fasting helped them to reduce biological markers of aging and disease, as well as decreasing their levels of bad cholesterol.
On the fasting day, people are only allowed to have zero-calorie drinks, such as unsweetened tea and coffee and water, or to chew sugar-free gum.
Studies on both mice and humans have shown that alternate-day fasting can be effective.
One study has tested the effects of alternate-day fasting on mice.
This also looked to see if fasting at 50 percent on one day followed by eating freely the next could be effective.
The results showed that total fasting one day was, unsurprisingly, the most effective.
However, 50 percent fasting on one day also reduced weight and improved the health of the mice.
The size of fat cells in the bodies of mice who fasted at 100 percent on alternate days was reduced by more than half.
Dr Thomas Pieber, co-author of the study on humans, said:
“Why exactly calorie restriction and fasting induce so many beneficial effects is not fully clear yet.
The elegant thing about strict ADF [alternate-day fasting] is that it doesn’t require participants to count their meals and calories: they just don’t eat anything for one day.”
Professor Harald Sourij, another co-author of the study on humans, said:
“We found that on average, during the 12 hours when they could eat normally, the participants in the ADF group compensated for some of the calories lost from the fasting, but not all.
Overall, they reached a mean calorie restriction of about 35% and lost an average of 3.5 kg [7.7 lb] during four weeks of ADF.”
The study was published in the Journal of Lipid Research (Varady et al., 2007).