Fat loss for the seriously overweight

This is the pillar page for everything we publish on fat loss. If you are 100kg or more and you have failed at this before, start here.

The problem with standard advice

Conventional guidance assumes a lean-ish person trying to get leaner. Small deficit, gradual habit change, patience. That works when you have 8kg to lose.

When you have 60kg to lose the arithmetic changes completely. A deficit that takes four years to finish is not a plan — it is a way of being on a diet forever, and nobody sustains that. The failure gets blamed on willpower when the real problem was the timeline.

What we do instead

1. A bigger deficit than you have been told to run

Rate of loss scales with how much fat you are carrying, and it scales for two reasons that compound. Your body can fuel a bigger deficit out of fat rather than muscle. And a bigger deficit is there to take — a 150kg man simply burns more, so the same 1,000 kcal off leaves him with a full plate and leaves a lean man hungry all evening.

So a genuinely obese man can lose 1.5–2.5kg a week and be comfortable doing it. The rate comes down as he leans out. That is the design, not a failure.

Work your own number out rather than taking one:

Sedentary burn is around 2,300 kcal for a 90kg man. Scale to your weight
Add 50 kcal per 10,000 steps, per 10kg of bodyweight — so 450 per 10,000 steps at 90kg
Take the deficit off that, and recalculate off this morning's weight, not the weight you started at

Then let the scale overrule all of it. If you think you burn 4,000, you eat 3,500, and four weeks later you weigh the same, you do not burn 4,000. Every number above is a starting point. Weight change over time is the only thing that settles it — if the maths and four weeks of seven-day averages disagree, the maths is wrong.

2. Protein held high throughout

1g per centimetre of height, every day. 180cm, 180g.

Simple enough to remember, and it beats the usual per-kilo formulas for one quiet reason: your height does not change while you are dieting. Set it once and it stays right the whole way down.

This is the guardrail that makes an aggressive deficit reasonable rather than reckless. It is what keeps the weight you lose weighted towards fat rather than muscle.

3. The floor is your intake, not your deficit

These are not the same thing, and confusing them is where people get hurt. Two men on an identical 1,000 kcal deficit can be eating 2,800 or 1,300 — completely different situations. What has to stay up is the food on the plate.

There is no single number for that floor. It moves with your weight and your activity. What does not move: when the arithmetic says eat less, moving more is the other option, and past a point that is the option to take.

4. Adherence is half the job

A relentlessly hungry and tired man will overeat sooner or later. That is not a character flaw, it is what happens to everybody given enough weeks, and any plan that ignores it works on paper and fails in a kitchen at eleven at night.

Which is why the best deficit is the most aggressive one you can actually manage — not the biggest the maths allows, and not a timid one either. Too small is a real failure, not the safe option: 100 kcal a day would take so long it is pointless.

It is also part of why we push a faster rate. Seeing real change every week is what makes the next week bearable.

5. How Mark trains through it

Mark's approach, not a house rule — he and David train people differently, and David's side of the business is strength.

Minimalist: two sets, progressive overload, taken to failure. Compound lifts. Full body, two or three times a week. Overload is scaled to the deficit — push hardest nearer maintenance, back off the harder you are dieting.

And no bulking, ever. You can build muscle at maintenance and lose fat in a deficit. The bulk/cut cycle most of the industry treats as the only route to muscle is not one we use, and for a man who has just spent a year getting the weight off, being told to put some back on is the last thing he needs to hear.

The three phases

Fat loss is not one experience. It is three, and what separates them is which measurement is telling you the truth. Someone who does not know which phase he is in will read perfectly normal progress as failure.

Phase	Roughly	The scale	The mirror	What to trust
1. Morbidly obese — the scale phase	down to ~30% bodyfat	moves fast, dramatically	nothing, for a long time	The scale
2. Obese — the grind	~30% → ~18%	slows right down	still not much	Tape measure, lifts, photos eight weeks apart
3. Normal — the mirror phase	~18% → ~12%	barely moves	a few pounds changes how you look	The mirror

Lean, for a man, starts at around 12% and below.

Phase 2 is where almost everybody quits — not at the start when it is hardest, but here, when it is working and does not look like it. The easy weight is gone by then, so what is left comes off at the speed fat comes off. Same effort, slower scale.

The fix is not more effort. It is changing which instrument you believe.

How long? Work it out: roughly 7,700 kcal per kilogram of fat. Mark's own phase 2 was 117kg to 100kg — about 17kg, so roughly 131,000 kcal of deficit, which at 1.5kg a week is eleven weeks. Round your expectations up, never down.

What this is not

Not a starvation protocol. An aggressive deficit with high protein is a different thing from crash dieting, and we are careful about the difference
Not nutrition or health advice. We do body composition — fat, muscle and strength. Micronutrients, bloods, gut health and anything medical belong to a professional, and we will tell you so rather than guess
Not for everyone. Already lean? Wrong page — go to the strength method
Not written for women. Mark has never trained one and has not lost weight as one. None of these numbers should be applied to a woman
Not medical treatment. A condition that affects weight, or any medication, means a conversation with your doctor first