What's the Best Diet for Losing Weight?
By Adi · October 19, 2026
Keto, low-fat, fasting or daily calorie control: an expert review found them similar. Pick a deficit you can keep, then lift and eat enough protein.
No diet type won. Keto, low-fat, intermittent fasting and daily calorie control all performed similarly, so the best diet is the deficit you can keep up, with lifting and enough protein.
That is the conclusion of a new expert review from the International Society of Sports Nutrition. It is not a single trial. It is a position stand, where a panel of researchers (Brad Schoenfeld is one of them) reads the literature and agrees on 15 points.
What the review looked at
The panel compared the main ways people eat to lose weight: how big the deficit is, whether it is the same every day, and what the mix of carbs, fat and protein looks like.
What they concluded
- Carbs vs fat: the range from ketogenic to low-fat diets performs similarly for weight loss. Pick the one you like.
- Fasting vs daily: alternate-day fasting, time-restricted eating and twice-weekly fasting showed no differential effect against eating a steady deficit every day.
- Meal frequency: how many times you eat per day does not tend to crucially change fat loss.
- Muscle: resistance training and enough protein are indispensable for keeping lean mass in a deficit, whatever diet you choose.
- Keto and muscle: ketogenic diets work for fat loss, but tended to cost more fat-free mass than higher-carb diets.
One line on crash diets: eating under 800 kcal a day, or 800-1200 kcal, loses more in the short term but showed no long-term advantage over a calorie-controlled diet. They may also cost more lean mass, and the panel warns about falling short on vitamins, minerals and fibre. This is not something to start on your own.
🏋️♂️ Key takeaways
- Choose the diet you can live with. The type matters less than whether you are still doing it in month three.
- Lift, and keep it doable. The review says resistance training is indispensable for protecting muscle in a deficit. It does not set a frequency. My own rule of thumb is 2-3 sessions a week you can actually keep.
- Hit a protein number. For the general population the review suggests 1.2-1.6 g per kg of body weight. With lifting, 1.6-2.2 g/kg may optimize muscle.
- Total protein first. It is the priority. The split across meals is secondary, though at least three protein-rich meals a day may help active people hold muscle in a deficit.
📲 Try it this week in Adi.Fit
This is how I would set it up for a busy week.
- Today: open Macros, set your goal and look at your protein target. For fat loss I start it at 2.2 g/kg, the top of that 1.6-2.2 range. The app counts it on the lower of your current weight and a weight at a BMI of 30, so it stays sensible if you carry a lot of extra weight.
- Every day: log your meals so you can see whether your protein and calories land where you planned.
- This week: pick a plan in Programs with 2-3 lifting days you can honestly keep.
⚠️ The catch
- It is a review, not a trial. It is the authors' reading of the evidence.
- Industry ties. Several authors report consulting for companies in nutrition and supplements, or scientific advisory roles with brands. The society itself is sponsored by supplement companies.
- Active, generally healthy adults. It leans on that group, with some clinical research where relevant. It does not cover weight-loss drugs or surgery, and it is not advice for any medical condition.
Quick answers
Do I need to fast to lose weight?
No. Fasting variants did not differ from a steady daily deficit. If skipping breakfast suits you, fine. If not, eat it.
How much protein is enough?
Start in the ranges above and adjust to your body and training. I go deeper on this in can your body only use 25-30 grams of protein per meal, and on setting targets in how to use macros right.
Where does the deficit come from?
Mostly the kitchen. See BMR, NEAT, TEF and why the kitchen rules fat loss.
Scientific reference: International Society of Sports Nutrition position stand: diets for body weight reduction. Aragon AA, Campbell BI, Schoenfeld BJ, et al. 2026. Journal of the International Society of Sports Nutrition.
PubMed 42867412 · doi.org/10.1080/15502783.2026.2740266