16:8 Intermittent Fasting: The World's Most Popular Protocol

The 16:8 protocol is the most researched and widely practiced form of intermittent fasting. You fast for 16 hours and eat within an 8-hour window each day. The most common setup is skipping breakfast and eating from noon to 8pm, though any 8-hour window works. Research consistently shows 16:8 reduces overall calorie intake by 10 to 20 percent without deliberate restriction, improves insulin sensitivity, and promotes fat oxidation.

Choose your 8-hour eating window and stick to it every day. Noon to 8pm is the most popular choice because the morning fast is mostly covered by sleep, and you only need to skip breakfast or push it back to midday. Eat two to three meals within your window. During the 16-hour fast, drink water, black coffee, or plain tea only. The protocol becomes automatic within two weeks as hunger hormones adapt to the new schedule.

• ✓Produces consistent fat loss without requiring calorie counting for many people
• ✓Backed by the most robust body of research of any IF protocol
• ✓Improves insulin sensitivity and fasting blood glucose in most practitioners
• ✓Skipping breakfast eliminates one daily eating decision and opportunity to overeat
• ✓Flexible: any 8-hour window works to fit social and work schedules

• ✗Requires skipping breakfast, which conflicts with morning exercise routines for some people
• ✗Social breakfast events and early morning meetings can disrupt the schedule
• ✗Hunger during the late morning can be intense in the first one to two weeks of adaptation