Cutting diet: a complete guide with real numbers

You dropped the first couple of kilos, then the scale stopped moving and your working weights started sliding backwards. Or you are about to start and have no idea how many calories to cut or how much protein you actually need. This is the arithmetic of a cutting phase: how big a deficit, how many grams of what, how many weeks, and what exactly to change when progress stops.

Pick the rate first, calories second

Most people choose a diet first and end up with whatever rate of loss falls out of it. Do it the other way round. A rate you can actually hold is 0.5 to 1 per cent of body weight per week. At 80 kg that is 0.4 to 0.8 kg.

Use the lower end if you are already fairly lean, if strength in the gym matters to you, or if you have three months or more to play with. The upper end mostly makes sense early on, while there is more fat to lose.

Below 0.3 per cent a week the change disappears into the daily noise on the scale and you cannot tell whether the plan works. Above 1 per cent a week three things show up reliably: strength drops, hunger eats your discipline, and more of what you lose is muscle.

Set the calories and leave them alone for two to three weeks

A kilogram of fat tissue is worth roughly 7,000 kcal. So half a kilo a week is about a 500 kcal daily deficit, and 0.3 kg a week is about 300 kcal. Those are the numbers you work with.

You need a starting estimate of maintenance. A rough figure for someone training three to five times a week and not glued to a chair the rest of the day is 29 to 33 kcal per kilogram of body weight. An 85 kg man lands somewhere around 2,500 to 2,800 kcal. If you have already logged your food for a week or two and your weight held steady, that number beats any formula, so use it. The full procedure is in the guide on working out calories and macros step by step.

Subtract your deficit and hold that number for at least two weeks, preferably three, before changing anything. Week one almost always shows a bigger drop than the real fat loss, because water and gut content go first.

Protein is the macro you lock in

In a deficit protein does two jobs: it protects muscle and it keeps you full. Aim for 1.8 to 2.4 g per kilogram of body weight. The leaner you are and the bigger the deficit, the closer to the top of that range you should sit.

At 80 kg that is 145 to 190 g a day. Spread it over three to five meals, 30 to 50 g each. A 150 g chicken breast gives about 45 g, 200 g of low-fat cottage cheese about 25 g, three eggs about 19 g, a scoop of whey about 24 g.

If you do not eat meat the target does not change, only the sources and the portion sizes do, which is covered in the piece on getting enough protein on a vegetarian diet.

Fat and carbs: splitting what is left

Do not push fat below 0.6 g per kilogram. Most people feel better at 0.8 to 1 g, simply because less fat usually means drier food and a worse mood. Everything left over goes to carbohydrate, which fuels your training and is the easiest thing to trim later.

An example, an 80 kg man on 2,100 kcal: 180 g of protein is 720 kcal, 65 g of fat is 585 kcal, which leaves 795 kcal, or about 200 g of carbs. That is plenty for three hard sessions a week.

Do not turn macros into a religion. If you hit your calories and your protein, and fat and carbs wobble by 15 to 20 g on any given day, the outcome will not change.

Make the deficit survivable

Diets do not fail because of metabolism. They fail because of hunger on a Tuesday evening. The fix is food volume per calorie. Put 400 to 600 g of vegetables and two pieces of fruit into your day and you will hit 25 to 35 g of fibre without thinking about it.

The things that help most:

• Protein and vegetables go on the plate first, everything else after them.
• Potatoes, beans, oats and fruit fill you up far more per calorie than biscuits and juice.
• Alcohol carries 7 kcal per gram and usually drags food along with it.
• Seven to nine hours of sleep measurably lowers hunger the next day.
• Drinking more and eating less means you lose salt faster than you expect.

Training decides what you look like at the end

The deficit decides how much you lose. Lifting decides what you lose. Without it a good share of those kilos comes out of muscle, and you end up looking the same, only smaller.

Hold 10 to 20 hard sets per muscle group per week, split across two sessions for each group. Work in the 5 to 15 rep range, stopping one or two reps short of failure.

The main rule: do not change your programme when you start cutting, and do not chase personal bests. The aim is to keep the weight on the bar. If after eight weeks in a deficit your squat and press sit on the same loads, you have done the job properly.

Steps and cardio: how much you actually need

Steps are the cheapest tool you have. 7,000 to 10,000 a day shifts the balance by a few hundred calories and takes nothing away from your recovery. What that means in real numbers is broken down in the article on walking and daily step counts.

Add cardio only once calories have nowhere left to go: two or three sessions of 20 to 30 minutes a week, on non-lifting days or after training. If you open with five hours of cardio a week, you have nothing left to add later.

Measure, then adjust

Weigh yourself every morning, after the toilet, before breakfast. Look only at the weekly average and compare it with last week's average. A single day tells you nothing.

Alongside that, measure your waist once a week and take photos every four weeks in the same light. For women it is normal for the average to hold or jump in the week before a period, then fall sharply afterwards.

If the average has not moved for three weeks running and you have genuinely been logging, change one thing: cut 150 to 250 kcal, or add 1,500 to 2,000 steps a day. Not both, or you will not know which one worked. A longer stall and its causes are covered in the article on weight loss plateaus.

Breaks and getting out of the diet

Run a cutting block for 8 to 16 weeks, then take a week or two at maintenance. Calories go up to your estimated maintenance and training stays the same. The scale will jump 0.5 to 1.5 kg from water and glycogen; that is not fat and it settles within days.

When you reach your target, do not jump straight back to your old intake. Add 100 to 200 kcal a week until you are back at maintenance, and keep weighing yourself. That stretch matters as much as the diet itself, and how to handle it across a full year is set out in the guide on keeping the weight off after a diet.

Common mistakes

Most failed cuts come down to one of these:

• Too big a deficit on day one. 1,200 kcal for a 90 kg adult lasts ten days and ends at the fridge at midnight.
• Logging on weekdays, free-styling at weekends. Two days at 1,200 kcal over wipe out five days at 500 kcal under.
• Not counting oil and spreads. A tablespoon of oil is 120 kcal; three a day is 360 kcal nobody sees.
• Changing the plan every five days. No plan gets long enough to show a result.
• Cutting protein instead of carbs. Trim the thing that is not protecting muscle first.
• Reaching for cardio first. You use up your options before you need them.

When to see a doctor

See a doctor if you are losing weight without trying, if your period stops or becomes irregular, or if you get persistent dizziness, fainting, a racing heart at rest or unusual exhaustion. The same applies if you have diabetes, thyroid, kidney or liver disease, if you are pregnant or breastfeeding, or if you take medication that food intake affects. A history of disordered eating is a reason to run a diet with professional support rather than on your own.

Common questions

Do I have to weigh my food?

Not forever, but yes for the first three or four weeks. Eyeballing portions is typically off by 20 to 40 per cent, and almost always in the same direction. Once you know what 150 g of rice and 40 g of peanuts look like, you can switch to estimating and weigh only occasionally.

Does fasted cardio burn more fat?

During the session itself, yes. Across 24 hours the difference is practically nil. Do your cardio whenever it suits you and does not wreck your lifting.

What about birthdays and meals out?

Plan for them. Keep the daytime light on protein and vegetables, leave 600 to 800 kcal for that meal, and go back to the plan the next day. One big meal a week will not undo a 3,500 kcal weekly deficit; a run of them will.

Will I lose strength?

A small drop at the end of a long cut is normal, especially on higher reps. If strength falls more than 10 per cent, or starts falling in week two, your deficit is too big or you are not sleeping enough.

The short version

Pick a rate of 0.5 to 1 per cent of body weight a week. Estimate maintenance at 29 to 33 kcal per kilogram and take off 300 to 500 kcal. Lock protein at 1.8 to 2.4 g per kilogram, keep fat at 0.6 g or more, and let carbs take the rest.

Lift each muscle group twice a week and walk 7,000 to 10,000 steps a day. Track the weekly average on the scale and change one variable only when three weeks pass with no movement. After 8 to 16 weeks take a break at maintenance, then bring calories back up slowly.