Intermittent Fasting Gains Traction for Weight Loss and Metabolic Health, but Long-Term Adherence Remains a Challenge

[medi K / HEALTH IN NEWS] Obesity ranks among the most pressing health crises of modern life. Globally, it drives cardiovascular disease, diabetes, and other metabolic disorders, spurring a proliferation of dietary strategies for weight control.

One approach drawing widespread attention is intermittent fasting (IF). Unlike conventional calorie-restricted diets, IF focuses not on how much is eaten but when, cycling between periods of eating and fasting to optimize the body’s metabolic rhythms.

Why Intermittent Fasting Is Generating Buzz

Traditional diets emphasize daily calorie reduction. Yet prolonged restriction often leads to hunger, fatigue, and stress, undermining adherence. Intermittent fasting shifts the emphasis to timing, aligning meals with the body’s circadian rhythm—the internal clock governing daily physiological cycles.

Common protocols include the 5:2 method (normal eating for five days, 400 to 600 calories on two non-consecutive days); alternate-day fasting (ADF), with full fasting one day and unrestricted eating the next; modified alternate-day fasting (MADF), limiting intake to 25 percent or less of energy needs on fasting days; and time-restricted eating (TRE), confining meals to an 8- to 12-hour window. These regimens are credited with recalibrating the biological clock and restoring metabolic efficiency more effectively than simple portion control.
What the Research Shows

In a 2022 paper, Yoon Jeong Cho, M.D., of Daegu Catholic University School of Medicine, synthesized clinical data on intermittent fasting’s impact on weight, glucose control, blood pressure, and lipid profiles.

The analysis compared the 5:2 diet, MADF, and TRE.

Dr. Cho’s team conducted a 12-week trial pitting the 5:2 protocol against continuous calorie restriction in overweight adults and patients with type 2 diabetes. A separate 10-week study tested MADF at 600 to 800 calories on fasting days. Another arm applied an 8- to 12-hour eating window, tracking weight, blood pressure, and inflammatory markers. Most trials lasted 3 to 12 months and enrolled primarily younger adults.

The results were encouraging across metabolic domains. The MADF group shed an average of 5.6 kilograms over 10 weeks—roughly 20 percent of baseline weight—matching outcomes from continuous restriction.

Glycemic and cardiovascular markers improved broadly. Both the 5:2 and MADF regimens lowered fasting glucose, blood pressure, total cholesterol, LDL cholesterol, and triglycerides. The 5:2 method proved particularly effective at reducing fasting insulin and insulin resistance.

A 16:8 schedule (16 hours fasting, 8 hours eating) trimmed weight and waist circumference while decreasing C-reactive protein (CRP) and oxidative stress—effects likened to a nightly metabolic “reset.” Some 5:2 participants, however, reported heightened hunger, highlighting adherence hurdles.

Proven Benefits, Persistent Questions

Dr. Cho’s work underscores intermittent fasting’s metabolic promise, yet limitations persist. Trials were short-term, leaving long-term efficacy and safety unproven. Participants skewed young and healthy; data on older adults, those with chronic conditions, or advanced metabolic disease remain sparse.

Patients with diabetes face hypoglycemia risk during fasting and require medical supervision. The approach is contraindicated for pregnant or breastfeeding women, growing adolescents, and individuals with eating disorders. In one study of type 2 diabetes patients, 27.1 percent of the intermittent-fasting arm dropped out—a signal that theoretical gains may falter in real-world practice.

Oh Ha Eun / press@themedik.kr

Copyright © 2020 mediK. All rights reserved.