The Method Weight loss
Is intermittent fasting better for weight loss?
Not when the calories are the same. A fasting window only works through the deficit it helps you keep.
StrongGood evidence, with a caveat worth knowing.
Updated . The Vanguard coaching team.
What most people miss
Intermittent fasting is a way of eating less, not a different way of losing fat. In a year-long trial, 139 people all cut their calories by 25%, and half of them also ate only between 8 a.m. and 4 p.m. They lost 8.0 kg against 6.3 kg, a gap the trial could not tell from chance.1
So the window is a tool, and its whole effect runs through the deficit. If skipping breakfast makes the day's food easier to control, it helps. If it leads to a bigger dinner, it does nothing.
What that trial did not measure is the part training cares about: what the weight lost was made of. Whatever the window, the things that protect muscle in a deficit still apply, protein among them.2
The research
The papers behind the answer
Each one checked against the paper itself. The grade describes the strength of the evidence, never anyone's results.
Liu, Huang, Huang et al., 2022 · N Engl J Med
Randomised trial · n = 139 · 12 months
Both groups cut calories by 25%. Adding an 8 a.m. to 4 p.m. eating window: 8.0 kg lost against 6.3 kg, a gap the trial could not tell from chance (p = 0.11).
Read the paper by Liu, Huang, Huang et al., 2022 (opens in a new tab)Helms, Zinn, Rowlands, Brown, 2014 · Int J Sport Nutr Exerc Metab
Systematic review · 6 studies · lean, trained, dieting
2.3 to 3.1 g per kg of lean mass, higher the leaner you are and the bigger the deficit. Few studies, so read the range as a guide.
Read the paper by Helms, Zinn, Rowlands, Brown, 2014 (opens in a new tab)
Research describes groups of people. Your coach will tell you how it applies to you.
From the floor
When you eat is yours to choose, and your coach trains around whatever window you keep. Personal food targets go to the registered dietitian in the building.
The Vanguard coaching team