One Day MD | Evidence-Based Wellness

By Dr. Frank Yap, MD | Medically reviewed by One Day MD Review Team | Last updated: September 29, 2026 Quick Answer: One Day MD is an independent, evidence-based health library covering supplements, longevity, GLP-1 and weight management, cancer prevention, heart and metabolic health, brain and sleep, immunity, skin, joints, family health and finding a specialist. Use this page as your map: check the date, pick a pillar, then narrow by label. Disclosure: Some pages link to products or partners, and we may earn a commission at no cost to you. This is educational content, not medical advice. In This Guide How to Use This Site Topic Index (12 pillars) Site Tools and Sister Sites AI Personalization Guide FAQ How to Use This Site 1 Check the date : Look for the Last updated line. 2026 guides use current evidence; older posts may not. 2 Pick a pillar : Match your question to one of the 12 pillars below and read its flagship guides first. 3 Narrow by label : Labels list every post on ...

GLP-1 medications can produce substantial weight loss, but the scale does not tell you whether that weight came from fat, lean tissue, or both. As semaglutide, tirzepatide and other incretin-based therapies become increasingly important in obesity treatment, a more useful question is emerging: how can weight be lost while preserving muscle, physical function and long-term health? Evidence review updated: September 28, 2026  |  Topic: GLP-1 medications, muscle loss, lean mass, metabolism and weight regain The evidence in one paragraph: Substantial weight loss from semaglutide, tirzepatide and other incretin-based therapies can include a measurable reduction in lean mass. However, a 2026 systematic review and meta-analysis found that the proportion of total weight lost as lean mass was broadly comparable with intensive lifestyle-based weight loss, rather than showing that incretin drugs uniquely cause muscle loss. The same analysis found the most favorable lean-ma...

By Dr. Frank Yap, MD | Medically reviewed by One Day MD Review Team | Originally published: August 24, 2026 | Last updated: September 29, 2026 Quick Answer: A healthy lifestyle may add years to life, and potentially a decade or more in some populations, but no scientifically valid number applies to everyone. The biggest gains come from not smoking, regular physical activity, a high-quality diet, a healthy body weight, and controlled cardiovascular and metabolic risk factors . One influential U.S. analysis projected about 14 more years for women and 12 for men at age 50 for people with five low-risk habits versus none, but that is an observational estimate, not a guarantee. Supplements and anti-aging drugs are not proven to add a specific number of years. Preventing falls and injury also protects healthspan: balance and strength training is the best-supported strategy. In this guide What the Best Evidence Shows Other Studies Point the Same Way How Much Does Each Lifestyle...