Nutrition7 min read
A steady, healthy way to gain weight as a beginner
Struggling to put on weight usually has little to do with finding a secret food. This guide is for healthy adults 18 and over who want a steady, sustainable way to gain, built on a small calorie surplus, enough protein and simple strength training.
The short answer
Gain weight healthily with a small surplus of roughly 10 to 15 per cent above your own estimated maintenance, which works out as a different number of calories for different people, 1.6 to 2.2g of protein per kilogram of bodyweight, and 2 to 3 full-body strength sessions a week. Weigh in weekly and target a gain of 0.25 to 0.5% of bodyweight per week, adjusting food if the scale stalls.
- Eat a small, consistent surplus rather than a huge one
- Prioritise protein at each meal
- Train your whole body 2-3 times a week
- Weigh in weekly and adjust food based on the trend
Why a slow, steady surplus beats eating everything in sight
It is tempting to think gaining weight means eating as much as possible, as often as possible. In practice this usually adds more body fat than muscle, which is not what most beginners actually want. A modest surplus, paired with strength training, gives your body the raw material to build muscle without piling on fat much faster than it can use it.
The target gain of 0.25 to 0.5% of your bodyweight per week is a useful guide because it is fast enough to see progress within a few weeks but slow enough that most of the gain is lean tissue. For someone weighing 65kg, that is roughly 160 to 325g a week, which works out at about 0.7 to 1.4kg a month.
Working out roughly how much to eat
You do not need to count every calorie forever, but it helps to have a starting estimate. A common approach is to take your bodyweight in kilograms, multiply by around 33 to 36 to estimate maintenance calories, then add 200 to 300 calories on top for a gaining phase.
Estimate your calories for gaining muscle
Around 2678 calories to stay the same weight
To build muscle, aim for roughly 2878 to 3028 calories a day. That is a small surplus, which should show up as about 0.19kg of weight gain a week. If the scales are climbing faster than that over a month, take a little back off.
Uses the Mifflin-St Jeor equation with a standard activity multiplier. Estimates like this are usually within a few hundred calories, so treat the number as a starting point and adjust it against your weekly weight trend. General information for healthy adults aged 18 and over, not medical advice. Nothing you type here is saved or sent anywhere.
| Bodyweight | Rough maintenance | Gaining target |
|---|---|---|
| 55kg | 1,815-1,980 kcal | 2,015-2,280 kcal |
| 65kg | 2,145-2,340 kcal | 2,345-2,640 kcal |
| 75kg | 2,475-2,700 kcal | 2,675-3,000 kcal |
| 85kg | 2,805-3,060 kcal | 3,005-3,360 kcal |
Training so the extra food becomes muscle
Food alone will not build muscle. You need a reason for your body to use the extra energy, and that reason is progressive resistance training. Beginners do well with full-body sessions two to three times a week, giving each major muscle group a chance to be worked with enough recovery between sessions.
Step 1
Pick compound lifts
Base sessions around squats, presses, rows and hip hinges that work several muscles at once.
Step 2
Use 2-3 sets of 6-12 reps
Stop each set one to three reps short of failure so you can recover for the next session.
Step 3
Train 2-3 times a week
Full-body sessions fit around most schedules and beat splitting muscle groups too early. They usually take around an hour, but the sets decide that, not the clock.
Step 4
Add weight gradually
Increase the load or reps slightly whenever a session feels manageable, which is what actually drives growth.
- Warm up with a lighter set before your working sets
- Keep a simple log of weights and reps so you can see progress
- Rest at least one day between sessions hitting the same muscles
Tracking your weight without obsessing over the scale
Bodyweight naturally fluctuates day to day with water, food and sleep, so a single reading tells you little. Weigh yourself at the same time each morning, ideally a few times a week, and look at the trend across two to three weeks rather than any one number.
- If your weekly average is not rising after 2-3 weeks, add roughly 150-200 calories
- If you are gaining faster than 0.5% of bodyweight a week, ease off slightly
- Track how your clothes and reflection look, not just the scale
Making it easy to keep going
The biggest reason people fail to gain weight is not a bad plan, it is inconsistency. Life gets busy, appetite dips, and the extra food gets skipped. Building weight-gain habits around meals you already enjoy makes it far more sustainable than following a rigid, unfamiliar diet.
What to do when the weight stops moving
A fortnight with no change almost always means one of two things: you are eating less than you think, or your daily activity has quietly risen. Neither is a failure of metabolism, and both have straightforward fixes.
Step 1
Check a fortnight, not a week
Compare weekly averages. One flat week is well within normal fluctuation.
Step 2
Record everything for three days
Include drinks, cooking oil and anything eaten standing up. Under-recording is very common.
Step 3
Add about 200 kcal a day
One extra snack is usually enough. Large jumps add fat rather than speed.
Step 4
Anchor the extra to a routine
The same snack at the same time each day is far more reliable than eating more in general.
Step 5
Re-check in two weeks
If the average is climbing by 0.2 to 0.5% of bodyweight a week, leave it alone.
Common questions
- How long does it take to gain weight healthily?
- With a steady surplus and consistent training, weight moves within a few weeks and changes in shape follow later, though how much later varies substantially from person to person. Gaining 0.25 to 0.5% of your bodyweight per week means the early changes are small but add up over months.
- Can you gain weight without going to the gym?
- You can gain weight without training by eating in a surplus, but without resistance exercise more of the gain tends to be fat rather than muscle. Even basic bodyweight or dumbbell training two to three times a week helps direct extra calories towards muscle.
- Why am I not gaining weight even though I eat a lot?
- It usually means your surplus is smaller than you think, since it is easy to underestimate portions and drinks. Track your food for a week, compare it against your target, and increase intake gradually if your weekly average weight is not moving.
- Is it normal to feel bloated when trying to gain weight?
- Some fullness or bloating is common when increasing food intake, especially with more fibre, dairy or large meals. Spreading food across more, smaller meals and easing into a higher intake over a couple of weeks usually settles this.
- Should skinny beginners do cardio while trying to gain weight?
- Light cardio is fine and supports general health, but too much can make it harder to eat enough surplus. Keep cardio moderate, for example a couple of short sessions a week, and prioritise strength training as the main driver of muscle gain.
- What if I gain weight but don't look more muscular?
- This usually means the surplus is a bit large for how much you are training, so more of it is going to fat. Trim the surplus slightly, keep protein consistent, and make sure your strength training is progressing week to week.
References
Every figure in this guide traces to one of these documents. Open them and check.
- Healthy ways to gain weight — NHS
- SACN dietary reference values for energy — Scientific Advisory Committee on Nutrition
- Progression models in resistance training for healthy adults — American College of Sports Medicine
Educational information for adults aged 18 and over. It does not diagnose, treat or manage any medical condition. If you have a health condition, or symptoms that worry you, speak to a qualified clinician.