Compare experts › Mary Claire Haver vs Jason Fung

Mary Claire Haver vs Jason Fung

Mary Claire Haver (physician, ob-gyn) 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.

Build a plan from both See the protocols

Words explained (11)

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.
Loaded carry: Walking while holding something heavy, like shopping bags or dumbbells.
Mobility: Moving your joints freely through their full range.
Creatine: A well-studied supplement that supports strength and muscle.
Omega-3 (EPA, DHA): Healthy fats found mostly in oily fish such as salmon, herring and sardines.
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.
Perimenopause: The years of changing hormones before periods stop for good.
Hormone therapy (HRT, MHT): Medicine that replaces hormones that fall at menopause. Only a doctor can prescribe it.

At a glance

Measure	Mary Claire Haver	Jason Fung
Background	Physician, OB-GYN	Physician, kidney specialist
Training split	55% strength · 40% aerobic · 0% intervals · 5% mobility	45% strength · 35% aerobic · 12% intervals · 8% mobility
Signature habit	Fibre 25 g+ a day	Fasting, less sugar
Protein	80–120 g a day	No fixed target
Training style	Women 40+	Fasting
Overall evidence	Strong	Mostly weak
Following	Instagram 3.6M · YouTube 688K	YouTube 1.5M

Training splits are our estimates from each expert’s published routine. Following checked October 2026.

The key differences

Haver puts more of the week into strength: about 55% against 45%.
Fung puts more of the week into intervals: about 12% against 0%.
In plans in their style, Haver's hard sessions are 1-minute intervals; Fung's are 4-minute intervals (Norwegian 4 × 4).
We rate the evidence behind Haver's protocol higher: strong, against mostly weak for Fung.
Supplements that go into a plan: Haver, none (food first); 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.

Protocols side by side

Each line is rated for the evidence behind it. “Doctor only” items never go into a plan.

Training

Mary Claire Haver

Full-body weight training at least 2 days a week (she does 3–4), progressing gradually, ideally with a trainerStrong evidence
Walk at least 3 days a week; beginners start with 5–10 minutes a dayStrong evidence
To progress: add a weighted vest to walks, more steps, or a third lifting dayPersonal habit
No exercise types need to be avoided in menopause; strength, cardio, stretching and mind-body work all matterNote

Jason Fung

No specific guidance in what we reviewed.

Eating

Mary Claire Haver

Protein about 1.5 g per kg of healthy body weight a day, with about 1.8 g/kg as a stretch goalSome evidence
Fibre at least 25 g a day, building slowly towards 30–45 gStrong evidence
Eat about 30 different plant foods a week (vegetables, fruit, nuts, seeds, grains, herbal teas)Some evidence
Anti-inflammatory, Mediterranean-style eating: limit added sugar and processed carbohydrate, add leafy greens, olive oil, berries, nuts and fermented foodsStrong evidence
Spread protein across meals and snacks, each paired with a healthy fat and a healthy carbohydratePersonal habit
She originally promoted 16:8 intermittent fasting but has pulled back, saying it can make enough protein hard to reachNote

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

Mary Claire Haver

Omega-3, vitamin D and vitamin K among the supplements she takes; she does not give general dosesPersonal habit
Fibre supplement if diet alone falls short of the daily targetPersonal habit
Check with your doctor before starting any new supplementNote
She sells her own supplement line ('Pause), so weigh her product recommendations with that in mindNote

Jason Fung

No specific guidance in what we reviewed.

Sleep & recovery

Mary Claire Haver

Menopausal hormone therapy, chosen with a doctor; she calls it the most effective treatment for hot flushes and night sweatsDoctor only
Prefers non-oral (patch, gel, spray) oestrogen, which carries a lower clot risk than tablets; progesterone for women with a uterusDoctor only
Magnesium (L-threonate) and a sleep supplement in her own routinePersonal habit

Jason Fung

No specific guidance in what we reviewed.

Stress & mind

Mary Claire Haver

Journal for a few minutes every dayPersonal habit
Add meditation, using an app or free guided sessionsSome evidence
Prepare questions before midlife health check-ups and push for proper care of symptomsPersonal habit

Jason Fung

No specific guidance in what we reviewed.

Brain health

Mary Claire Haver

Points to observational data linking longer lifetime oestrogen exposure, including hormone therapy, with better cognition; not a licensed reason to start hormonesDoctor only
Creatine for possible memory and mood benefits; most of this evidence is from small or non-menopausal studiesSome evidence
Strength training, protein and fibre as part of reducing long-term risks such as dementia, heart disease and diabetesSome evidence

Jason Fung

No specific guidance in what we reviewed.

Weak spots to know

Mary Claire Haver

Several menopause specialists, quoted in a 2024 New York Times report, said she promotes hormone use beyond official guidelines; one said patients now ask for hormones to prevent heart disease or dementia, or testosterone for general wellbeing.
Commercial ties, stated neutrally: she owns The 'Pause Life (a multimillion-dollar business selling supplements, programmes and online courses) and a cash-pay menopause clinic. The Menopause Society discourages doctors from selling their own products, and the advertising watchdog Truth in Advertising flagged some product claims; according to the New York Times, she then hired a consultant to review the claims on her website.
An independent review by ConsumerLab found some of her supplements costly for what they contain, with creatine claims that overstate the evidence and a vitamin D dose at the upper safe limit.

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 Haver, 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.

Plan in Haver's style Plan in Fung's style Mix both

Questions

What is the main difference between Mary Claire Haver and Jason Fung?

Their training split differs most in intervals: Haver about 0%, Fung about 12% (our estimate from their published routines). Haver's signature habit is Fibre 25 g+ a day; Fung's is Fasting, less sugar.

How much protein do Haver and Fung recommend?

Haver: 80–120 g a day. Fung: No fixed target.

Whose advice has stronger evidence?

We rate the evidence behind Haver's protocol higher: strong, against mostly weak for Fung.

Do Haver and Fung disagree?

Not directly in what we reviewed. Their differences are in emphasis: haver puts more of the week into strength: about 55% against 45%.

Can I combine Haver 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: Mary Claire Haver · Jason Fung. Reviewed October 2026.