Guide · Food and modes · 3 min read

Protein when your appetite is low

By the CalJab team, with sources · Last reviewed October 21, 2026

When you lose weight, you can lose muscle as well as fat. ¹ In one study, about 38% of the weight lost was lean mass, including muscle. ¹ Eating little protein because of low appetite can also add to muscle loss. ¹

How much

• The general adult recommendation is 0.8 g per kilogram a day; higher targets such as 1.2 to 1.6 g have been proposed during weight loss. ¹
• With obesity, it is not clear whether to use actual or adjusted body weight; using actual weight can overstate how much you need. ¹
• Long-term intake of 2 g per kilogram or more should be avoided. ¹

Protein when you eat less

• Choose lower-volume, nutrient-dense foods: fish, eggs, Greek yogurt, cottage cheese, nuts and seeds, peanut or almond butter. ¹
• Some people top up with high-protein shakes, bars or fortified products. ¹
• Don't go too long without eating. Small, regular meals are advised. ¹

Protein alone is not enough

To protect muscle you need regular strength training alongside protein; protein alone is likely not enough. ¹ Aerobic exercise alone does less to protect muscle during fast weight loss. ¹

If you use FODMAP mode

Most legumes are high FODMAP; eggs, firm tofu, tempeh and plain cooked meat, poultry and seafood are low FODMAP. ² Marinated or processed meats may contain high FODMAP ingredients such as garlic and onion. ²

In CalJab

While you are losing weight, your protein target is worked out at 1.5 g per kilogram, using an adjusted weight if your weight is well above the ideal range. You can change it in Your targets. Today shows how much protein is left, your plan is built protein first, and Recipes has sippable options for low appetite days. The protecting muscle card in Body shows strength workouts from Apple Health.

You can set your protein target together with your doctor or a dietitian.

Written by the CalJab team, with sources. It does not replace your doctor's advice. Found a mistake? Write to support@caljab.app.