Peer-reviewed study
Fasting works when it helps the deficit
Intermittent fasting and weight loss: Systematic review
Kris Oddo, NASM-certified personal trainer, is the founder and head coach of Gains From Geebs (Geebs Coaching), a 1:1 online fitness coaching practice.
Quick answer
What this study found
Intermittent fasting can provide a helpful structure, but it does not create a magic metabolic advantage.
How strong is this kind of study?
- Reviews of many studiesThis study
- Controlled trials
- Observational
- Narrative reviews
Systematic review. Heavier plates are built from more studies, so they move less when the next one lands.
At a glance
What kind of study this is
Strongest evidence
This pools results from many separate studies, so it carries more weight than any single trial on its own.
- Design
- Systematic review
- Published
- 2020
- Journal
- Canadian Family Physician
- Reference
- PMID 32060194
Honest limits
What this study does not prove.
Fasting does not outperform calorie restriction for everyone. Its fit depends on appetite, schedule, protein intake, and health context; medical use belongs with a clinician.
Kris's practical takeaway
Here's what to do with it.
Intermittent fasting can provide a helpful structure, but it does not create a magic metabolic advantage.
Ways to use it
Safe ways to apply it.
Fasting is a schedule, not a spell
The deficit still decides
Use fasting only if it makes the week easier
Related questions
Questions this research helps answer.
Fasting and fat-loss answer
Is intermittent fasting better than calorie restriction?
Intermittent fasting can work when the eating window makes a calorie deficit easier to sustain. It is not automatically better than ordinary calorie restriction, especially if the shorter window makes protein harder to hit.
Fasting and muscle answer
Will intermittent fasting cause muscle loss?
Intermittent fasting does not automatically cause muscle loss. The risk shows up when the shorter eating window makes calories, protein, or training quality drop low enough that the body has less reason and less material to keep muscle during a cut.
Related guides and studies
Keep learning about nutrition.
FAQ
Quick questions
What is the practical takeaway from this study?
Intermittent fasting can provide a helpful structure, but it does not create a magic metabolic advantage.
What does this study not prove?
Fasting does not outperform calorie restriction for everyone. Its fit depends on appetite, schedule, protein intake, and health context; medical use belongs with a clinician.
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25 lbAverage fat loss across 15 completed clients tracked over 16 weeks. Individual results vary.
1 of 3
2 months coachedDown 10 pounds and carrying more confidence into daily life.
Justin · 24 · 2 months coached“I've lost 10 lb, which has definitely given me more confidence. I'm not as tired during work and I can lift things easier than before.”
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6 months coachedFrom zero pull-ups to five on his own.
Jon Miller · 27 · 6 months coached“Before I couldn't do a single pull-up, and now I can do five all on my own.”
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3 months coachedBetter technique, better health, and support to keep going.
Jhoan Rincon · 46 · 3 months coached“Kris changed the way I view my life. Even though I do not have much free time, he helps me push myself to keep going and never lets me give up.”
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Pick the one that fits your week.
You have read the argument. These are the options, and whichever one you pick carries into the application.
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Most hands-onYou want a coach on training, food and accountability every day.- Daily replies, usually within the hour
- FaceTime meal prep: cook, portion, freeze the week
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Core 1:1You want a coach with you daily, without the concierge layer.- Custom training plan with demo videos
- Macros-based nutrition, no rigid meal plan
- Daily accountability at standard priority
New, self-drivenYou run your own week and want a coach reading the numbers.- Custom training and nutrition plan
- One recorded Loom review of your week
- Adjustments based on what the week showed
One-time guidanceYou want direction now without a monthly commitment.- A focused 45-minute Zoom with Kris
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- Guidance on training, nutrition, accountability, or schedule
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