InfoSearched
Intermittent fasting isn’t one plan — it’s a ladder, and Dr. Becky Gillaspy just laid out every rung.
In her video “3 Ways To Do Intermittent Fasting: Easy, Medium & Extreme,” Dr. Becky Gillaspy, author of the Intermittent Fasting Diet Guide and Cookbook, breaks the practice into three tiers based on how tight the eating window gets. Rather than chasing juice cleanses or colon detoxes, her framework is built entirely around time-restricted eating schedules — when you eat matters as much as what you eat. She walks through the entry-level 12:12 split, the widely studied 16:8 protocol, and the extreme end of the spectrum that includes OMAD and multi-day fasts.
- The “Easy” tier is the 12:12 method — a 12-hour fast and 12-hour eating window, typically finishing dinner by 7:00 p.m. and eating breakfast at 7:00 a.m.
- The “Medium” tier is the 16:8 protocol, fasting 16 hours and eating within an 8-hour window, often by skipping breakfast, which Gillaspy says lowers circulating insulin and stimulates growth hormone to preserve lean muscle.
- The “Extreme” tier covers 20:4 fasting, One Meal a Day (OMAD/23:1), and multi-day fasts of 24 hours or more, which Gillaspy warns can make hitting full micronutrient and calorie needs difficult.
The Easy Entry Point: 12:12
Gillaspy positions 12:12 as the on-ramp for anyone who has never structured their eating around a clock. The math is simple: finish dinner by 7:00 p.m., go to sleep, and don’t eat again until 7:00 a.m. Because roughly half the fasting window overlaps with sleep, she frames it as the least disruptive way to start building the habit before tightening the window further.
The Medium Protocol: 16:8
The 16:8 schedule is the one most researchers and dieters actually study and recommend, and Gillaspy treats it as the workhorse tier. Most people get there by skipping breakfast and confining meals to an 8-hour block in the afternoon and evening. According to Gillaspy, the extended fasting stretch drops circulating insulin low enough to shift the body toward burning stored fat, while simultaneously triggering a rise in growth hormone that helps protect lean muscle mass during the process — the combination she says makes 16:8 the sweet spot for sustainable fat loss.
Tighter windows can break a stubborn weight-loss plateau — but the tighter the window, the harder it gets to hit your nutrient targets.
The Extreme Tier: 20:4, OMAD and Multi-Day Fasts
At the far end of Gillaspy’s ladder sits 20:4 fasting, where the eating window shrinks to just four hours, and One Meal a Day — also called 23:1 or OMAD — where a single sitting covers the day’s entire intake. Beyond that are extended fasts stretching from a full 24 hours to several days at a time. Readers who’ve tried the OMAD route specifically can compare notes with Why One Meal A Day Is Good For You, and those curious about longer stretches without food have a real-world case study in 30 Days of Alternate-Day Fasting, which tracked ten pounds of body fat lost over a month.
The Trade-Off Gillaspy Wants You to Weigh
Gillaspy is careful not to sell the extreme tier as automatically better. She notes that narrower windows can be useful for pushing through a weight-loss plateau that a 16:8 schedule has stopped moving, but the shorter the eating window, the harder it becomes to pack in enough calories and micronutrients — a gap that risks metabolic slowdown and muscle loss if it drags on. Her guidance is direct: multi-day fasting should be done under medical supervision, not attempted solo based on a video. Anyone building out a broader fat-loss plan alongside their fasting window might also look at 3 Science-Based Tips to Lose Belly Fat for what to do inside the eating window itself.
The takeaway from Gillaspy’s breakdown isn’t “go extreme” — it’s start at 12:12, see how your body handles it, and only climb the ladder to 16:8 or beyond if the easier tier stops producing results. For most people watching her video looking for a starting point, that first rung is still the one she recommends stepping onto first.
A Navy SEAL Explains Why You Should End A Shower With Cold Water
Early Pregnancy Back Pain
The Golden Spice: A Closer Look at Turmeric
What is Qi Gong? Taoist Master explains power of Qi and philosophy
Tony Horton’s Insane Home Gym Tour