How fast to lose fat without losing muscle
About 0.5–1% of bodyweight a week keeps more muscle and performance, slower if you are already lean. The evidence, the safe floors and a worked example.
How fast should you lose weight on a cut?
In trained people, losing about 0.5–1% of bodyweight a week holds on to lean mass and performance better than losing faster. If you’re already lean, stay at the slower end. Faster loss only makes sense if you have a lot of fat to lose, and under supervision.
At 90 kg, for example, 0.5–1% is 0.45–0.9 kg a week. At 65 kg and already lean, about 0.3 kg a week is a sensible pace.
| Bodyweight | Slower end | Faster end |
|---|---|---|
| 60 kg | 0.30 kg | 0.60 kg |
| 70 kg | 0.35 kg | 0.70 kg |
| 80 kg | 0.40 kg | 0.80 kg |
| 90 kg | 0.45 kg | 0.90 kg |
| 100 kg | 0.50 kg | 1.00 kg |
Turning a rate into a calorie deficit
As a first approximation, a kilogram of body weight is about 7,700 kcal. So losing 0.5 kg a week takes a deficit of roughly 550 kcal a day (0.5 × 7,700 ÷ 7).
That’s only a starting point. As you lose weight, the same intake produces slower loss, so the target gets corrected from your measured trend.
| Weekly pace | Daily deficit |
|---|---|
| 0.25 kg a week | 275 kcal |
| 0.5 kg a week | 550 kcal |
| 0.75 kg a week | 825 kcal |
| 1 kg a week | 1,100 kcal |
The calorie floors Laroa won’t go below
The 2013 AHA/ACC/TOS obesity guideline uses 1,200–1,500 kcal a day for women and 1,500–1,800 for men when an individual deficit isn’t calculated. Lower intakes belong under medical supervision.
Laroa also keeps any target within 30% of your maintenance. That’s a conservative limit of its own. It doesn’t come from the guideline.
| Maintenance | Women | Men |
|---|---|---|
| 1,800 | 1,260 | 1,500 |
| 2,200 | 1,540 | 1,540 |
| 2,600 | 1,820 | 1,820 |
| 3,000 | 2,100 | 2,100 |
Keep the muscle
Higher protein reduces lean-mass loss on a cut, especially if you’re lean and trained. Laroa works within about 1.8–2.7 g/kg of bodyweight a day while you lose fat.
Signs you’re cutting too fast
Persistent fatigue, falling performance, frequent illness or injury, or lost or irregular periods are warning signs of low energy availability. Ease the deficit and see a clinician.
How fast to gain on a bulk
Going the other way? If you’re building muscle, the matching guideline is to gain about 0.25–0.5% of bodyweight a week. Beginners can sit at the top of that range. Faster gain is mostly fat.
| Bodyweight | Slower end | Faster end |
|---|---|---|
| 60 kg | 0.15 kg | 0.30 kg |
| 70 kg | 0.18 kg | 0.35 kg |
| 80 kg | 0.20 kg | 0.40 kg |
| 90 kg | 0.23 kg | 0.45 kg |
| 100 kg | 0.25 kg | 0.50 kg |
Common questions
Is losing 1 kg a week safe?
If you have a lot of fat to lose, 1 kg a week can be within 1% of your bodyweight. For most people who train, 0.5–1% of bodyweight a week is the better target, and faster loss belongs under supervision.
What is the least I should eat?
Without medical supervision, about 1,200 kcal a day for women and 1,500 for men. Laroa also never goes more than 30% below your maintenance.
The evidence behind this guide
Each claim above traces to an entry in Laroa’s evidence base (version 2026-10-17.1), which summarises position stands, guidelines and meta-analyses and grades how strong each one is.
- Rate of fat lossModerate evidence
- Weight change is not linearModerate evidence
- Unsupervised calorie floorStrong evidence
- Protein while losing fatModerate evidence
- Low energy availability (REDs)Strong evidence
- Rate of gain while building muscleModerate evidence
Sources
- Helms ER, Aragon AA, Fitschen PJ. Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. J Int Soc Sports Nutr. 2014;11:20. doi:10.1186/1550-2783-11-20
- Hall KD, Sacks G, Chandramohan D, et al. Quantification of the effect of energy imbalance on bodyweight. Lancet. 2011;378(9793):826-837. doi:10.1016/S0140-6736(11)60812-X
- Trexler ET, Smith-Ryan AE, Norton LE. Metabolic adaptation to weight loss: implications for the athlete. J Int Soc Sports Nutr. 2014;11:7. doi:10.1186/1550-2783-11-7
- Jensen MD, Ryan DH, Apovian CM, et al. 2013 AHA/ACC/TOS guideline for the management of overweight and obesity in adults. Circulation. 2014;129(25 Suppl 2):S102-S138. doi:10.1161/01.cir.0000437739.71477.ee
- Jäger R, Kerksick CM, Campbell BI, et al. International Society of Sports Nutrition position stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20. doi:10.1186/s12970-017-0177-8
- Loucks AB, Thuma JR. Luteinizing hormone pulsatility is disrupted at a threshold of energy availability in regularly menstruating women. J Clin Endocrinol Metab. 2003;88(1):297-311. doi:10.1210/jc.2002-020369
- Mountjoy M, Ackerman KE, Bailey DM, et al. 2023 International Olympic Committee's (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs). Br J Sports Med. 2023;57(17):1073-1097. doi:10.1136/bjsports-2023-106994
- Iraki J, Fitschen P, Espinar S, Helms E. Nutrition recommendations for bodybuilders in the off-season: a narrative review. Sports. 2019;7(7):154. doi:10.3390/sports7070154
General information for healthy adults, not medical advice. If you have a medical condition, are pregnant, or have pain or warning symptoms, ask a clinician.
