A recent diet trend is alternate-day fasting (ADF). As its name suggests, alternate-day fasting involves fasting for a day and eating whatever you like without restrictions the next day. It is one of the several varieties of intermittent fasting.
Although it can appear extreme to some people, alternate-day fasting is safe and has many health benefits, according to a study published in the journal Cell Metabolism.
Alternate-day fasting: Safe and beneficial for the body
In the randomized controlled trial study, the researchers looked at the effects of ADF on healthy, normal-weight individuals. Over the course of four weeks, they randomly assigned 60 participants to either ADF or to a control diet that involves eating as much as they wanted.
Those assigned to the former regimen alternated 36 hours of zero-calorie intake with 12 hours of unlimited eating. They went through regular glucose monitoring to ensure that they did not consume any calories during fast days. Furthermore, they were asked to document their fasting days.
The researchers also studied 30 individuals who previously practiced more than six months of strict ADF. They compared them to normal, healthy control individuals with no fasting experience. The purpose of this adjunct study was to examine the long-term safety of ADF.
The team discovered the following health benefits from ADF:
- Reduced belly fat
- Reduced markers of age-associated disease and inflammation
- Lower levels of cholesterol
- Lower levels of triiodothyronine without impaired thyroid gland function. Previous research has linked decreased levels of this hormone to longevity in humans.
- Increased and sustained ketone bodies even on non-fasting days. Higher levels of ketones in the body are linked to lower blood pressure, increased insulin sensitivity and enhanced cognition.
The researchers also found that while participants on ADF regained some of the calories lost due to fasting, the total calories that they consumed were still less than they would typically consume on a normal diet. The team estimated that the ADF group reduced total caloric intake by an average of 35 percent and lost an average of 7.7 pounds.
“The elegant thing about strict ADF is that it doesn’t require participants to count their meals and calories: they just don’t eat anything for one day,” added co-author Thomas Pieber of the Medical University of Graz in Austria.
Furthermore, while previous research suggested calorie-restrictive diets can result in malnutrition and impaired immune function, the participants on six months of ADF exhibited stable immune function.
Senior author Frank Madeo of the University of Graz explained that the reason behind this particular finding may have to do with evolutionary biology: “Our physiology is familiar with periods of starvation followed by food excesses. It might also be that continuous low-calorie intake hinders the induction of the age-protective autophagy program, which is switched on during fasting breaks.”
The researchers reiterated that some types of diet are more appropriate for other people. ADF may work better for obese people and for those with inflammatory diseases. But people fighting a viral infection should refrain from fasting as their immune system needs immediate energy to fight viruses. (Related: Reduce inflammation in the gut with the “fasting-mimicking” diet.)
The next step for the researchers is to study the effects of strict ADF on different groups of people such as those with obesity and diabetes. They also plan to compare ADF to other dietary patterns and explore its mechanisms.
Learn more about different diet types and their benefits at Slender.news.