4 fasting myths that dieticians want you to stop believing

Intermittent fasting and OMAD (one meal a day) have gained popularity in the internet, but experts say many of the claims surrounding these diet strategies are misunderstood.

In an interview with GMA News Online, nutritionist-dieticians Bernice Sabenicio and Christian Jay G. Vasquez share common misconceptions and myths about fasting.

'I can eat anything during my eating window'

Sabenicio said that one popular misconception is that in intermittent fasting, you can eat "unlimited junk food" during your eating window.

"Food quality still matters. A person can fast but still consume excessive calories or lack important nutrients," she said.

Vasquez added, "If your daily energy expenditure is 2,000 calories and you consume 2,500 calories during an OMAD meal, you will store the excess energy as fat."

'Fasting only burns fat, not muscle'

When you lose weight, you also lose muscle mass.

"One misconception is that these diets will burn fat only," Sabenicio said. "That is not the case because extreme restriction can also affect muscles and other parts of the body."

If done irresponsibly, fasting can lead to muscle deterioration., Vasquez explained.

Citing the Journal of the International Society of Sports Nutrition, he said, "The human body can only optimize a finite amount of protein for muscle building at one time. Compressing protein intake into a single daily spike limits Muscle Protein Synthesis (MPS), severely risking muscle wasting over time."

'Skipping breakfast puts my body into starvation mode'

It takes more than missing breakfast for the body to enter "starvation mode," clinically termed adaptive thermogenesis, Vasquez said.

"This is a real biological preservation mechanism, but it does not trigger from skipping breakfast," he said.

Citing the journal Obesity, he added that significant metabolic slowdown requires weeks or months of severe, chronic caloric deprivation.

"Short-term fasting actually triggers a transient increase in resting metabolic rate due to an evolutionary spike in counter-regulatory hormones like epinephrine," he said.

'OMAD burns more fat than other diets'

Vasquez said that it's true that fasting accelerates "autophagy," the cellular self-cleaning process.

Howwver, this biological function is accelerated by any form of energetic stress.

"[This means] a standard, well-managed daily calorie deficit triggers cellular cleanup without needing to endure a 23-hour fast," he said.

Sabenicio also stressed that OMAD may lead to nutrient deficiencies "because it can be difficult to meet daily needs for macronutrients and micronutrients in one meal."

"It may also lead to muscle loss, low energy, overeating, constipation, and bad breath," she added. —JCB, GMA News