What to Eat in a Calorie Deficit: Foods That Fill You Up

Foods that fill you up in a calorie deficit give you the most grams and the most protein for each calorie. On my own plate that usually means potatoes, beans, fish, eggs or plain yogurt, with whatever vegetables are in the fridge filling the rest. In a 1995 test of 38 foods served in equal-calorie portions, boiled potatoes scored 323% on a fullness scale where white bread scored 100%. A butter croissant scored 47%.

Which foods fill you up for the fewest calories?

Start with water. It adds weight without adding calories, so a watery food weighs a lot per calorie and a bigger portion fits the same budget. The label for this is low energy density, which means few calories per gram.

Food (state)	kcal per 100 g	Grams for 100 kcal	Protein per 100 kcal (g)
Cucumber, with peel, raw	14	714	4.3
Iceberg lettuce, raw	14	714	5.0
Zucchini, raw	16	625	6.3
Strawberries, raw	33	303	1.8
Broccoli, boiled	35	286	6.9
Carrots, raw	45	222	2.0
Apple, gala, raw	55	182	0.2
Greek yogurt, nonfat	61	164	16.9
Potato, boiled in skin	87	115	2.2
Lentils, boiled	116	86	7.8
Brown rice, cooked	123	81	2.2
Egg, whole	147	68	8.4
Whole-wheat bread	254	39	4.8
Popcorn, air-popped	387	26	3.3
Cheddar	408	25	5.7
Croissant, butter	406	25	2.0
Almonds, raw	584	17	3.7
Olive oil	884	11	0.0

Each row shows what 100 kcal weighs. Every row comes from a USDA FoodData Central record. I kept the cooking state in the name, since boiled and raw versions of a food aren’t the same food. Cucumber and lettuce top the list, and olive oil sits at the bottom. A 100 kcal portion of boiled potato weighs 115 g, and the same energy in almonds weighs 17 g.

Popcorn shows where weight alone misleads. Air-popped popcorn has 387 kcal per 100 g, yet a cup of it weighs only 8 g, so 100 kcal is about three cups.

A trial points the same way. Among the 71 women who finished a one-year trial, the group told to cut fat and eat more water-rich fruit and vegetables lost 7.9 kg. The group told only to cut fat lost 6.4 kg. The first group also reported less hunger.

Pick the two rows you already like and make them half of a plate this week.

The ranking has a catch. A food at the top of the table is only useful if you will eat it, and a plan built on plain cucumber won’t last a week. So I treat the list as a toolbox. Zucchini folded into pasta sauce, or strawberries after dinner, is how the top rows end up on a plate that still tastes like food.

Which calorie deficit foods give the most protein per calorie?

Shrimp, cod, tuna and chicken breast lead, and lentils trail, with eggs just ahead of them.

Food (state)	kcal per 100 g	Protein per 100 g (g)	Grams for 20 g protein	kcal for 20 g protein
Cod, cooked	84	20.4	98	82
Shrimp, cooked	99	24.0	83	83
Tuna, canned in water, drained	90	19.0	105	95
Chicken breast, braised	166	32.1	62	103
Greek yogurt, nonfat	61	10.3	194	118
Cottage cheese, 2% fat	84	11.0	182	153
Tofu, firm, raw	144	17.3	116	166
Egg, whole	147	12.4	161	237
Lentils, boiled	116	9.0	222	258

The cost of the same 20 g of protein runs from 83 kcal in shrimp to 258 kcal in lentils. Twenty grams from cod costs 82 kcal, and from eggs 237 kcal. That’s a gap of 155 kcal at one meal.

Protein earns a table of its own. The Dietary Guidelines for Americans set 1.2 to 1.6 g per kg of body weight a day. They also say to prioritize protein foods at every meal. At 70 kg that is 84 to 112 g a day, or roughly 28 to 37 g across three meals.

Lentils look expensive in the table. The same record lists 7.9 g of fiber per 100 g. So 20 g of protein from lentils comes with about 17.5 g of fiber, and the cod record lists none. Eggs and tofu cost more calories per gram of protein than fish, and they’re still fine. I use all of them and weigh each.

What does research say about feeling full?

That’s solid enough to guide a swap, though thin as the only basis for a whole diet. In the 1995 study, groups of 11 to 13 people each ate one of 38 foods, in servings of 1,000 kJ (240 kcal). They rated their fullness for two hours. Equal-calorie servings differed a lot in how satiating they were. Most foods (76%) scored at least as high as white bread, and boiled potatoes scored about seven times the croissant.

Treat it as a hint, since it measured two hours after one serving, not a diet.

A different kind of study asks about processing. In an NIH ward study, 20 adults ate as much as they liked. They spent 2 weeks on an ultra-processed menu and 2 weeks on an unprocessed one, matched on presented calories, sugar, sodium, fiber and macronutrients. Intake ran 508 kcal a day higher on the ultra-processed menu. Weight rose 0.9 kg there and fell 0.9 kg on the other.

I take it as a nudge to cook more of the plate myself. Twenty adults in a research ward aren’t your kitchen, so I wouldn’t turn it into a banned list.

Do I have to give up higher-calorie foods?

No. Weigh them and give them a slot. Thirty grams of almonds is 175 kcal. One slice of cheddar, 17 g, is 69 kcal, and a tablespoon of olive oil, 13.5 g, is 119 kcal. A medium butter croissant, 57 g, is 231 kcal.

The same 200 kcal buys 34 g of almonds, 230 g of boiled potato, 328 g of Greek yogurt or 364 g of apple. None of those is wrong. They fill a different amount of plate, so choose the one that matches how hungry you are. Banning the dense ones is how people drift toward a 1000 calorie deficit, which is too much for most adults. For the hours between meals, calorie deficit snacks lists options under 200 kcal, and eating fast food in a calorie deficit covers the drive-through.

How do I use this at the next meal?

Choose a protein from the second table, a bulky food from the first, and a measured spoon of fat. Tonight I’d plate cod 150 g (126 kcal) and boiled potato 200 g (174 kcal). Add broccoli 150 g (53 kcal) and olive oil 9 g (80 kcal). That’s 433 kcal and 38.0 g of protein.

The plate only matters against a daily budget, and what a calorie deficit is explains how to set one. The calorie calculator shows how many calories your own day has for a plate like that, using your age, height, weight and activity, and its NASEM 2023 equations return no less than 1,200 calories on the female formula or 1,500 on the male one.

These food lists are for adults who want to lose weight. If you’re pregnant, breastfeeding, under 18, living with a health condition or on medication, your doctor’s plan comes before any table of mine.

If counting calories has started to feel hard to stop, or eating feels out of control, talk to someone: ANAD in the US (1-888-375-7767), Beat in England (0808 801 0677), NEDIC in Canada (1-866-633-4220) or the Butterfly Foundation in Australia (1800 33 4673). If you’re in danger right now, call your local emergency number. Other UK numbers and crisis lines are on our crisis support page.