Start with calories
Weight loss requires an energy deficit over time: using more energy than you take in. Estimate your maintenance calories first. The calculator’s weight-loss option reduces that estimate; it cannot predict your exact rate of loss.
A larger deficit is not automatically better. If you are persistently exhausted, hungry, struggling to recover or becoming distressed about food, reassess the plan.
Keep protein in the plan
Adequate protein and resistance training can help preserve muscle during weight loss. People who train often use about 1.6–2.2 g/kg/day as a starting range, but needs vary with body size, health and the size of the deficit.
Use a realistic target, then include protein foods in meals you already eat. A very high target that crowds out other foods is not automatically more effective.
Choose your carbs and fat
There is no single best macro percentage for weight loss. Carbs can support training and supply fiber; fats provide essential fatty acids and help with vitamin absorption. Choose amounts that leave room for both.
The adult fat reference range is 20–35% of calories. After choosing protein and fat, you can assign the remaining calories to carbs. This is one planning method, not the only way to eat well.
One worked example
At an illustrative 1,800 calories, 130 g protein provides 520 calories. Choosing 60 g fat provides 540 calories. The remaining 740 calories provide 185 g carbohydrate. These numbers show the calculation; they are not a universal weight-loss plan.
What if your weight is not changing?
Compare several weeks under similar conditions before changing your intake. Water, digestion and menstrual-cycle changes can hide a trend. Check whether portions, drinks, sauces or your activity have changed, rather than assuming your metabolism is broken.
Weight is only one check. Energy, recovery, hunger and whether you can live comfortably with the plan matter too. A qualified clinician or dietitian can help if your situation needs more than a general estimate.
Do carbs have to be low?
No. Lower-carb and lower-fat approaches can both support weight loss. The useful question is which meals help you maintain an appropriate intake while meeting your nutritional needs.