Answer · 2026

I have 400 calories left and need 40g of protein. What should I eat?

A leftover meal of 400 calories and 40 g of protein is 10 g of protein per 100 calories. Chicken breast, canned tuna, cottage cheese, Greek yogurt, or a 42 g shake all fit, with calories left. Six whole eggs do not: they blow past 400 calories first. This is not medical advice.

Updated October 10, 2026 · Written by LAYERTWO, the makers of NutriCam. We make NutriCam. The food amounts on this page are ISSN’s, USDA’s, and fairlife’s. The other apps are not ours. This is not medical advice.

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Foods that hit 40 g inside 400 calories

Food	Protein	Calories	Left inside 400
Roasted chicken breast, 130 g (about 4.6 oz), meat only	40 g	215 kcal	185 kcal for fruit, rice, or vegetables.
Canned tuna in water, 6 oz (170 g) drained	40 g	218 kcal	182 kcal. The locker-bag tin, doubled.
Nonfat Greek yogurt, 400 g	40 g	235 kcal	165 kcal. About two 170 g cups plus extra spoons.
fairlife Core Power Elite, 14 oz	42 g	230 kcal	170 kcal. If you would rather drink it.
Low-fat (1%) cottage cheese, 1½ cups (339 g)	42 g	245 kcal	155 kcal. A cold bowl, no stove.

Chicken is USDA FDC 171477, read October 10, 2026: 165 kcal and 31 g of protein per 100 g of roasted, skinless breast, scaled to 130 g. Tuna, yogurt, and cottage cheese are the same USDA rows as the 3 oz / 170 g / 1 cup servings: FDC 175158, 170894, and 173417, scaled to 40 g. Elite is fairlife’s 42 g label, same date. Brands of yogurt and cottage cheese vary. Read the cup in your fridge.

Forty grams of protein costs 160 calories at 4 kcal per gram. That leaves 240 calories for everything else, which is why the protein has to be lean. The leftover 155–185 kcal can be fruit, rice, or vegetables. Oil, sauce, cheese, and a heavy dressing spend that leftover fast.

What blows the 400-calorie budget

Food	Protein	Calories	Why it misses
Six large hard-boiled eggs	38 g	468 kcal	Over 400, and still 2 g short. The yolk is mostly fat.
Three large hard-boiled eggs	19 g	234 kcal	Fits the calories. Hits only half the protein.
fairlife Core Power, 14 oz (not Elite)	26 g	170 kcal	Fits the calories. Leaves you 14 g short.

One large hard-boiled egg is 6.3 g of protein and 78 kcal on USDA FDC 173424, read October 10, 2026. Six eggs are 38 g and 468 kcal. People reach for eggs because they are already in the fridge. They are the wrong density for this leftover. The 26 g Core Power is fairlife’s 26 g label, same date.

Peanut butter and granola fill the calorie budget and barely move protein. Save them for a day when protein is already done. If the 40 g hole is the job, the food has to be lean.

The 160-calorie floor

Protein is 4 kcal per gram. Forty grams cannot cost less than 160 calories. A leftover of 400 calories that still needs 40 g is a 10 g-per-100-kcal plate. That is why chicken, tuna, cottage cheese, and a 42 g shake work, and why six whole eggs do not.

The ISSN 2017 protein position stand names 20–40 g of high-quality protein, or about 0.25 g per kilogram of body weight, as a usual serving that stimulates muscle protein synthesis. Spread those servings every 3–4 hours. Daily intake for most people who train sits at 1.4–2.0 g per kilogram. During a cut, the same paper raises that to 2.3–3.1 g per kilogram to keep lean mass. This leftover meal can be one of those 20–40 g servings. It is not the whole day.

ISSN also says supplements are a practical way to hit protein while keeping calories down. That matters when leftover calories sit near 200, not 400. The whole-food 40 g servings above land at 215–245 kcal. Isolate is the squeeze. Read the tub; scoop sizes vary. The leftover meal is one serving. Daily total is still the main job: what to eat after a workout if you are short on protein.

If leftover calories came from the watch

A lot of “400 calories left” includes exercise the watch added back. Treat that bonus as a guess. Welling’s FAQ, read October 10, 2026, says most wearables overestimate burn, and you can stop adding activity calories to the daily target. If the 400 leftover is half eaten-back exercise, the real leftover is smaller, and the 40 g hole gets tighter.

Remaining protein from the food log is the cue. The watch bonus is a maybe. If you are on a cut and not hungry, you do not have to spend the leftover calories. If you still need the 40 g, spend them on the lean rows above, not on the bonus the watch invented.

What an app can know, and what it cannot

Job	Who does it	What it does not do
Food ideas for remaining calories and protein	MyFitnessPal Nutrition Coach	Help page uses “I have 400 calories left and I’m 20g short on protein” as the example question. Needs today’s diary. Cannot log the meal. Premium, iPhone, six countries.
Chat ideas for remaining calories and macros	Welling	FAQ: ask for ideas for what is left. Photo, text, or voice log. Wearable burn is a guess. iPhone and Android.
Weekly calorie and macro targets that adapt	MacroFactor	Wins adaptive targets. Product pages describe weekly calorie and macro changes. We found no tonight-plate claim. iPhone and Android.
A fast photo count of protein on the plate	Cal AI	Calories, protein, carbs, and fat from a photo. Site, read October 10, 2026, does not describe a next-meal answer. iPhone and Android.
A next-meal answer from today’s log and the workout	NutriCam	App Store listing names recipes from remaining macros. Does not plan training, compute adaptive TDEE, or time carbs for an endurance event. iPhone only.

No phone sees lunch unless you log it. Photograph it, say it, scan it, or type it. Then remaining calories and protein are a real number. MyFitnessPal’s Nutrition Coach, read October 10, 2026, tells you to be specific: it uses “I have 400 calories left and I’m 20g short on protein” as the example of a useful question. Coach reads the diary you already kept. Welling answers in chat. MacroFactor is the better pick if the job is a target that moves with your weight trend. Cal AI is the better pick if the job is a fast count and you are on Android.

NutriCam, which we make, photographs a meal or takes a spoken sentence, then answers what to eat next from today’s log, targets, workouts, and Apple Health sleep when connected. The App Store listing, read October 10, 2026, names recipes based on remaining macros for the day and dietary preferences. Confirm the portion before you trust the remaining grams.

Dinner from a logged workout: apps that suggest dinner from a workout and what you already ate. How a next-meal answer is built: what should I eat next. What the app is: what is NutriCam. Photo numbers are estimates: how accurate are AI photo calorie counting apps.

Eat the lean protein, then log the plate. NutriCam is an iPhone advisor: photograph a meal or say what you ate, confirm the estimate, and see remaining calories and protein. It does not plan training, compute adaptive TDEE, or time carbs for an endurance event, and it is not on Android.

No app can measure a meal from a photo. A picture cannot show oil, sauces, hidden ingredients, or portion weight. Every number from every app on this page is an estimate until you correct the foods and portions. We have not run an accuracy test across these apps, so this page makes no accuracy ranking.

FAQ

Can I hit 40 g of protein in 400 calories with whole eggs?

No. One large hard-boiled egg is 6.3 g of protein and 78 calories (USDA FDC 173424). Six eggs are 38 g and 468 calories: short of 40 g and over 400. The yolk is mostly fat. Use chicken, tuna, cottage cheese, yogurt, or a 42 g shake.

Should I eat back the calories my watch added after the gym?

Treat them as a guess. Welling’s FAQ says most wearables overestimate burn, and you can stop adding activity calories to the daily target. If the 400 leftover includes eaten-back exercise, the real leftover is smaller. Remaining protein from the food log is the cue. This is not medical advice.

Is a protein shake the only leftover-protein meal that fits?

No. 130 g of roasted chicken, 6 oz of tuna in water, 400 g of nonfat Greek yogurt, and 1½ cups of 1% cottage cheese all hit about 40 g inside 400 calories. A shake wins when you will not eat. ISSN says high-quality protein from food or a supplement is the serving.

What if I only have 200 calories left and still need 40 g of protein?

Forty grams costs 160 calories at 4 kcal per gram, so 200 leftover leaves 40 calories of slack. The whole-food 40 g servings on this page sit at 215–245 calories. ISSN says supplements are a practical way to hit protein while keeping calories down. Read an isolate label. This is not medical advice.

Do peanut butter or granola close a leftover protein hole?

No. They fill the calorie budget and barely move protein. Use them when protein is already done. For a 40 g hole inside 400 calories, the protein has to be lean: chicken, tuna, cottage cheese, yogurt, or a labeled shake. Save the nut butter for a day when protein is already hit.

Is leftover-macro food advice from an app medical advice?

No. ISSN 2017 is a sports-nutrition position stand. USDA numbers are food composition, not a prescription. None of the apps on this page is a medical device. Nutrition from a photo is an estimate. See a clinician for medical nutrition.

Sources

Every fact about another app on this page comes from that app’s own site, help center, or store listing, checked October 10, 2026. Prices and features change. Check the live listing before you buy.