Effects of intermittent fasting on bone health

Intermittent fasting (IF), according to a number of studies, encourages weight loss and enhances metabolic health, but its impact on bone health is unknown. Researchers recently summarized the research on the effects of different IF strategies, including the 5:2 diet, alternate day fasting (ADF), and time-restricted eating/feeding (TRE/TRF), on bone health. The British Journal of Nutrition publishes this review.

The MEDLINE database was used by the authors of this study to find pertinent articles up until September 30, 2022. Animal research as well as human observational and interventional studies in adult populations were used to evaluate the effect of IF on bone health.

Short-term fasting is a relatively new phenomenon, despite the fact that it has been performed for centuries during holy occasions like Ramadan. This sort of fasting is also known as IF, which started being practiced in the last decade. It is a novel strategy for enhancing metabolic health and encouraging weight loss.

IF has swiftly gained popularity as a way to consume less calories. According to a recent survey, one in four US citizens have either tried or are considering using IF. Also, numerous research on IF showed that it significantly enhances blood lipid profiles, decreases blood pressure, and increases insulin sensitivity.

In contrast to conventional fasting, intermittent fasting (IF) involves daily energy limitation. In this scenario, total or significant energy restriction takes place within a set amount of time.Finding out how IF affects various body systems, including the skeletal system, is crucial. Weight loss is linked to a drop in bone mass, which could have an impact on bone microstructure. Biomarkers, bone measures, or substitute endpoints can all be used to examine bone mass or density, strength, and structure.

A typical method for determining bone mineral content (BMC) and areal bone mineral density is dual-energy X-ray absorptiometry (DXA) (aBMD). pQCT, or peripheral quantitative computed tomography, is another method for calculating volumetric BMD and bone geometry (vBMD). To measure changes in the rates of bone production and resorption, researchers utilize bone turnover markers (BTMs).Animal studies have been conducted to understand the effect of IF on bone health. These studies have revealed that IF, in addition to a high-fat or ketogenic diet, negatively affected bone health. The effect of a ketogenic diet with or without ADF was studied using a rat model. This study showed that rats subjected to ADF and a ketogenic diet exhibited inhibition in osteoclast proliferation and osteogenic differentiation.

Compared to the control group of rats subjected to a regular diet, rats under the ADF ketogenic diet showed decreased bone strength and poor overall bone health. In addition, the control group possessed reduced bone resorption and higher bone formation markers levels compared to the rats under the daily ketogenic diet and ADF ketogenic diet. Furthermore, TRF that involved three hours of feeding per day for 4 weeks showed reduced femoral BMD. Hence, TRF was found unable to protect bones from adverse effects. In contrast, TRE regimes practiced for a relatively short period of up to six months did not show any adverse effects on bone.