How much protein do I need while losing weight?

Protein requirement goes up when you are losing weight, not down. The 2025 joint advisory from the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association and The Obesity Society sets the target at 1.2 to 1.6 g/kg per day during active weight reduction. The general population reference figure of 0.8 g/kg is a minimum to avoid deficiency, not a target for someone in a substantial energy deficit.

How to work out your own number

Take your weight in kilograms and multiply by 1.2 and by 1.6 to get your range. An 80 kg adult lands at 96 to 128 g a day. A 110 kg adult lands at 132 to 176 g. The advisory itself notes an unresolved question: whether the target should be based on actual body weight, an adjusted body weight, or fat-free mass. At a very high starting weight, actual body weight produces a figure that is difficult to eat, and using an adjusted weight is reasonable. This is worth asking your clinician rather than guessing.

Why hitting the target is harder on a GLP-1

Protein is the most filling macronutrient, which is helpful when you are trying to eat less and unhelpful when your stomach is already emptying slowly. Patients routinely tell me meat feels heavy and they have drifted to toast, fruit and soup. That drift is where lean mass is lost. Eating the protein portion of the meal first, while the appetite window is open, is the most practical fix. Distributing intake across three or four eating occasions works better than one large evening meal, because a suppressed appetite rarely permits a large evening meal.

Count your protein for three ordinary days before you assume you are hitting the target. Most people are 30 to 50 g short and have no idea. If you cannot reach the number with food while appetite is suppressed, a protein supplement is a reasonable tool, and it is one of the few supplements in this area with a clear rationale. Fluid, fibre and a general multivitamin also matter, because total food volume falls and micronutrient intake falls with it.