- Weeks 1 and 2 are for baseline numbers and habits, not aggressive dieting.
- Aim for 0.5 to 1% of body weight a week once the deficit is set.
- Review at the halfway point and adjust one thing at a time.
- Week 12 is about moving to maintenance, not celebrating with a blowout.
Before you start
Take your starting measurements: weight (averaged over a few mornings), waist, photos, and one strength and one fitness marker, such as a set of goblet squats and a 1 km row. Write down why you are doing this, beyond a number. Then clear space in the diary for three training sessions a week.
If you have a medical condition, take regular medication or have been inactive for a long time, speak to your GP first. And pick a realistic target. At 0.5 to 1% of body weight a week, 12 weeks typically means somewhere around 4 to 10 kg for most people, depending on where you start.
Decide in advance what you will do on the harder days: the late meeting, the birthday, the week the kids are ill. Having a minimum version of the plan ready, such as two sessions and protein at every meal, stops a bad week from turning into a lost month.
Weeks 1 and 2: foundations
Resist the urge to slash calories straight away. The first fortnight is about finding your numbers and building habits that will carry the rest of the plan.
- Track your food honestly to find your maintenance. See maintenance calories.
- Hit a protein target of roughly 1.6 to 2.2 g per kg of body weight a day, or base it on goal weight if you have a lot to lose.
- Find your average daily steps, then add 2,000.
- Train three times a week: two strength sessions and one conditioning session, or three full-body strength sessions.
- Aim for at least seven hours in bed each night.
- Move or clear out the foods you most often overeat, so the easy choice at home is the one that fits the plan.
Many people lose some weight in these two weeks just from the structure and better food choices, before any deliberate deficit. Enjoy it, but do not expect it to continue at the same rate.
Weeks 3 to 6: the deficit
Now set a deficit of around 15 to 25% below maintenance. Keep protein where it is and take the reduction mainly from carbs and fats. Calorie deficit explained shows how.
- Training: keep three or four sessions a week and focus on getting stronger on your main lifts, as covered in strength training for fat loss.
- Steps: hold your new target every day, especially at weekends.
- Food: build default breakfasts and lunches, and plan one or two meals out a week rather than letting them happen by accident.
- Check-in: each week, compare your average weight with the previous week and write it down.
Expect the first couple of weeks of the deficit to feel the hardest while your body adjusts. Hunger usually settles once meals become routine, especially with enough protein, fibre and sleep.
Week 7: the halfway review
Halfway through, take a proper look. Measure your waist, take photos and compare them with your starting set, and retest your strength and fitness markers.
- Losing 0.5 to 1% a week and feeling good: carry on exactly as you are.
- Losing less than that for three weeks: tighten up tracking, bring steps back up and, if needed, trim 100 to 200 kcal. See how to break a weight loss plateau.
- Losing faster and feeling drained: add some food back, especially around training.
- Tired, stalled and hungry: consider a one-week break at maintenance, as explained in diet breaks.
Whatever you decide, change one thing and give it time to work before changing anything else.
Weeks 8 to 11: push on
This is where consistency pays off. The novelty has worn off and life will test you with birthdays, work stress and bad weather. Keep the basics going: protein, steps, three or four sessions and sleep.
Try to add a rep or a little weight to your main lifts every week or two, and keep conditioning to one or two sessions. If motivation dips, look back at your notes and photos from the start. Progress is usually more visible than it feels day to day.
This is also a good time to add one new habit, such as a 10-minute walk after dinner or an extra portion of vegetables at lunch, rather than cutting food further.
Week 12: finish well
Repeat your starting measurements and compare. Then, rather than ending the diet with a blowout, move gradually to maintenance over the next two to four weeks, adding around 100 to 200 kcal a day each week while keeping protein, training and steps the same. Expect a small scale bump of 1 to 2 kg from water and glycogen, and do not panic about it.
Then decide what comes next: another fat loss block after a few weeks at maintenance, a strength or fitness goal, or a longer spell of maintenance to lock in the new habits. Our guide on keeping the weight off covers that next phase.
Doing it with a coach
A plan on paper is one thing. Sticking to it for 12 weeks through real life is another. Coaching, a regular class slot and people to train with make a big difference to consistency, and consistency is what turns a plan into results.
Lycan Strength's 7-day free trial includes unlimited classes and a complimentary fitness assessment, which makes a natural week one for a plan like this. If you prefer to go it alone, find at least one form of accountability: a friend doing the same plan, a shared spreadsheet or a weekly message to someone you trust.
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Questions
How much weight can I lose in 12 weeks?
At a sustainable 0.5 to 1% of body weight a week, roughly 4 to 10 kg for most people, depending on starting weight.
Should I start with a big calorie cut?
No. Spend the first one or two weeks finding your maintenance and building habits, then set a moderate deficit.
What should I do after 12 weeks of dieting?
Move gradually to maintenance over two to four weeks, then decide whether to run another block later.
How often should I train on a 12-week plan?
Three or four sessions a week, mostly strength training, plus daily walking.
General guidance for healthy adults. If you have a medical condition, injury or are pregnant, check with a health professional before changing your training or diet.
