Calories
From our Jason Fung profile
Fung says hormones, not calories, drive weight; Norton and most researchers say total calories decide weight change, with protein and food quality shaping how it feels.
Compare experts › Layne Norton vs Jason Fung
Layne Norton vs Jason Fung
Layne Norton (nutrition scientist, powerlifter) and Jason Fung (physician, kidney specialist) side by side: how they train, eat, supplement and sleep, how strong the evidence is, and how to build a plan from either or both.
Words explained (9)
- Zone 2
- Steady cardio at a pace where you can still talk in full sentences, but not sing.
- Intervals
- Short hard efforts with easy recovery in between, such as 30 seconds fast, 90 seconds slow.
- 4 × 4
- Four rounds of 4 minutes hard with 3 minutes easy in between. Also called Norwegian intervals.
- Hypertrophy
- Muscle growth.
- Mobility
- Moving your joints freely through their full range.
- Leucine
- A building block of protein that helps switch on muscle building. Meat, fish, eggs, dairy and soy are rich in it.
- Creatine
- A well-studied supplement that supports strength and muscle.
- Fibre
- The part of plant foods you don't digest. It feeds healthy gut bacteria and keeps you full.
- Time-restricted eating
- Eating all your meals within a set window of the day, for example 8am to 6pm.
At a glance
| Measure | Layne Norton | Jason Fung |
|---|---|---|
| Background | Nutrition scientist, powerlifter | Physician, kidney specialist |
| Training split | 65% strength · 25% aerobic · 10% intervals · 0% mobility | 45% strength · 35% aerobic · 12% intervals · 8% mobility |
| Signature habit | Tiered supplements | Fasting, less sugar |
| Protein | 1.6–2.2 g/kg | No fixed target |
| Training style | Numbers-first | Fasting |
| Overall evidence | Strong | Mostly weak |
| Following | Instagram 1.2M · YouTube 439K | YouTube 1.5M |
Training splits are our estimates from each expert’s published routine. Following checked October 2026.
The key differences
- Norton puts more of the week into strength: about 65% against 45%.
- Fung puts more of the week into aerobic base (zone 2): about 35% against 25%.
- In plans in their style, Norton's hard sessions are 1-minute intervals; Fung's are 4-minute intervals (Norwegian 4 × 4).
- We rate the evidence behind Norton's protocol higher: strong, against mostly weak for Fung.
- Supplements that go into a plan: Norton, creatine monohydrate, whey protein, caffeine before training; Fung, none (food first). Prescription items and personal stacks stay out of every plan.
- Neither has a separate mobility routine; plans add 10 minutes a day of basics.
Where they disagree
Protocols side by side
Each line is rated for the evidence behind it. “Doctor only” items never go into a plan.
Training
Layne Norton
- Lift weights consistently, year after year, and take sets close to failureSome evidence
- Exercise improves health markers even when it does not change your weightStrong evidence
- Track daily steps while dieting: everyday movement tends to drop as calories fallSome evidence
- His PHAT programme: 5 days a week, two heavy 'power' days plus three higher-rep hypertrophy daysPersonal habit
Jason Fung
No specific guidance in what we reviewed.
Eating
Layne Norton
- Track calories and protein; food labels can be ~20% off, but consistent tracking still shows your true intake over timeSome evidence
- Weigh yourself each morning and compare weekly averages, not single daysSome evidence
- Protein about 1.6 g/kg a day; up to ~2.2 g/kg when dieting or very leanStrong evidence
- Choose a diet style you can sustain; low-carb and low-fat work equally well with calories and protein matchedStrong evidence
- Fibre about 15 g per 1,000 kcalSome evidence
- Seed oils are fine: replacing saturated fat with polyunsaturated fat lowers LDL and heart riskSome evidence
Jason Fung
- Cut added sugar and refined grains; eat whole foods with natural fats.Some evidence
- Stop snacking: three meals a day, then skip one meal a day.Personal habit
- Eat within a shorter window of the day (time-restricted eating).Some evidence
- Fasts of 24 hours (skipping two meals in a row) two or three times a week, as used in his clinic's programme.Personal habit
- Longer fasts of several days; in 2016 he said fasts of up to a month were fine.Doctor only
- For type 2 diabetes: no sugary drinks, fructose or processed food, and more natural fats.Doctor only
Supplements
Layne Norton
- Tier 1 – creatine monohydrate 3–5 g a day; loading is optional; timing does not matterStrong evidence
- Tier 1 – whey protein 20–40 g per serving (about 2–3 g leucine) to help reach daily proteinStrong evidence
- Tier 1 – caffeine 3–6 mg/kg about 45–60 min before training; lower doses still help alertnessStrong evidence
Jason Fung
No specific guidance in what we reviewed.
Sleep & recovery
Layne Norton
- Avoid caffeine late in the day; it can harm sleep even if you fall asleep normallyStrong evidence
- Carb timing matters little on average; if carb-heavy meals make you sleepy, move themNote
- Poor sleep and unmanaged stress are bigger problems than small nutrition detailsNote
Jason Fung
No specific guidance in what we reviewed.
Weak spots to know
Layne Norton
- Commercial ties: he co-founded Outwork Nutrition, which sells whey protein and products containing creatine — overlapping with his Tier 1 list — and co-founded the paid Carbon Diet Coach app and the BioLayne coaching business. He has also disclosed past research funding from the National Dairy Council, the National Cattlemen's Beef Association and the Egg Board.
- Reverse dieting, which he helped develop and popularise, had no published controlled trials supporting it as of 2021; its use rests mainly on coaching experience.
- His relaxed view of seed oils is contested by others in the health space. On The Drive (2026), Peter Attia presented the strongest case against seed oils for a debate after the booked guest declined, while saying his own view is close to Norton's; debate continues over older trials and LDL oxidation.
Jason Fung
- Red Pen Reviews scored The Obesity Code at 31% for scientific accuracy, and The Diabetes Code at 33%.
- His central claim that calories do not matter is contradicted by controlled studies.
- Much of his support comes from case reports, small older studies and his own clinic.
Build a plan from Norton, Fung or both
Your free plan shows a week of gym sessions, cardio, a day of eating, supplements and mobility, fitted to your age, time and health.
Questions
What is the main difference between Layne Norton and Jason Fung?
Their training split differs most in strength: Norton about 65%, Fung about 45% (our estimate from their published routines). Norton's signature habit is Tiered supplements; Fung's is Fasting, less sugar.
How much protein do Norton and Fung recommend?
Norton: 1.6–2.2 g/kg. Fung: No fixed target.
Whose advice has stronger evidence?
We rate the evidence behind Norton's protocol higher: strong, against mostly weak for Fung.
Do Norton and Fung disagree?
Yes, on calories. See "Where they disagree" on this page.
Can I combine Norton and Fung?
Yes. In Build my mix you choose one expert per area, for example one for strength and another for eating. Your free plan shows the result straight away.
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Full sources are on each profile: Layne Norton · Jason Fung. Reviewed October 2026.