The intermittent weight-watcher

A time-restricted feeding strategy can assist in calorie reduction by synchronising the diurnal pattern of insulin secretion, boosting gastrointestinal motility, and maximising energy synthesis from carbs, writes Dr Praveen Kumar Kaudlay

All over the world including India, this generation is turning out to be obese with attended metabolic disorders. In 2019, estimates showed India has 77 million diabetics, which is expected to rise to 134 million by 2045. The family health survey (NFHS-S) shows an increasing burden of obesity in the population with one in four persons now obese in India. This does not include many in the pre-diabetes category who would soon become diabetic.

The increase in obesity and diabetes is leading to a significant cardiovascular burden and mortality. Turning out to be a public health issue, much of the focus around the world has shifted to addressing obesity through drugs and non-pharmacological interventions.

There is a buzz around two drugs for weight loss — Ozempic (approved for diabetes in the USA) and Wegovy (licensed). Both contain Semaglutide, which mimics GLP-1 (Glucagon-like Peptide) — a hormone that tells the brain that “the stomach is full, no need to eat more”. There is so much demand for these drugs that there is a shortage of both in the USA. However, they are not without side effects. Those using the drugs to reduce weight have started to look a lot older, something called Ozempic face. The drugs are expensive, and upon discontinuation, the weight returns eventually.

Extreme cases of obesity are dealt with through bariatric surgery. Given the limitations of pharmacological limitations, the emphasis is now shifting to the practice of intermittent fasting (IF). When we consume a meal, the glucose levels peak within the first hour, followed by a steady return in the second hour. The fat component called TAG (Triacylglycerols) peaks after 3-5 hours and remain higher even at six hours. With the second and the third meal, both glucose and fat remain high throughout the day making it conducive for fat to get stored.

Obese individuals have resistance to the hormone that tells the brain to be full, they tend to be hungrier, and they have a resistance to insulin action and thus tend to have high blood sugar developing into diabetes.

It began with Dr Michelle Harvie’s work at the University of Manchester UK in 2011 with overweight women at risk of breast cancer. That study showed that intermittent fasting improved glucose regulation and other risk factors for cardiovascular disease and some cancers. Then the documentary produced by the BBC aroused interest in this area. Dr Mark Mattson, a Professor of Neuroscience at Johns Hopkins University school of medicine USA, is one of the leading authorities in intermittent fasting. The
author of the NEJM (New England Journal of Medicine) review article and author of the book The Intermittent Fasting Revolution observes, “The scientific evidence suggests that our body and brain evolved to adapt for intermittent eating.” He suggests one could pursue either the 16:8 fasting (16 hours of fasting) or 5:2 (2 days in a week fast or low-calorie consumption). It might be easier for people to adopt time-restricted feeding, aiming for 16-18 hours of daily fasting. This time-restricted feeding concept is based on matching the diurnal rhythm of insulin secretion, more gut motility, and more energy production from the carbohydrates that happen during the daytime rather than at night.

Between 12-16 hours of fasting, the benefits of ketones start manifesting. It helps in waste removal and recycling inside a cell, called autophagy. This helps in maintaining a healthy cell function. Fasting has also been observed to reduce inflammation, being beneficiary in arthritic conditions, and may delay the onset and progression of Alzheimer’s dementia and Parkinson’s disease and improve brain cognition.

In a cancer setting, intermittent fasting is thought to inhibit the growth of cancer cells and make them susceptible to chemotherapy drugs. In lab experiments, rats that fasted on alternate days with a low protein diet lived fifty percent longer. Further, age-related cancers and degeneration of nerves slowed down, and biomarkers that suggest ageing were reduced with fasting. Dr Vijay Vishwanathan, vice president, of the Research Society for the Study of Diabetes in India [RSSDI], recommends intermittent fasting as a good option to consider in a predominantly carbohydrate-consuming population of India. The obese and the pre-diabetics are particularly the most beneficiary group. Those on insulin should discuss with their physicians before resorting to intermittent fasting, cautions Dr Vishwanathan.

“Remember, our ancestors’ adaptations in a food-deprived state are still in our genes, cells, and organs, we need to be persuasive for intermittent fasting with attended health benefits.” Dr Mattson’s words should be motivating enough.

(The author is a consultant haemato-oncologist with a special interest in stem cell transplantation at Royal Wolverhampton NHS Trust, UK. He can be reached at [e-mail])