5 foods under 400 calories per 100 g
Every food in this band is dry, and every one of them roughly triples in weight when you cook it. That is not a coincidence — it is the whole reason the figures look alarming.
| Food, dry | kcal per 100 g |
|---|---|
| Lentils | ~353 |
| Plain flour | ~364 |
| White rice, raw | ~365 |
| Quinoa | ~368 |
| Pasta | ~371 |
| Rolled oats | ~379 |
Also on this rung: couscous (376), cornmeal (370), rice cakes (387), sugar (387), air-popped popcorn (387), honey (304) and dried dates (282).
Dry weight and cooked weight are different foods
A hundred grams of dry rice is 365 kcal. A hundred grams of cooked rice is 130. Both numbers are correct and they describe the same grain.
What changed is water. Rice absorbs two to three times its own weight, so 100 g dry becomes roughly 280 g on the plate — same 365 kcal, spread across nearly three times the weight.
| Food | Dry, 100 g | Cooks to | Cooked, per 100 g |
|---|---|---|---|
| White rice | 365 kcal | ~280 g | ~130 |
| Pasta | 371 kcal | ~235 g | ~158 |
| Lentils | 353 kcal | ~300 g | ~118 |
| Rolled oats | 379 kcal | 400–530 g | ~71–95 |
Porridge is the extreme case. The same 379 kcal of oats can read as 95 kcal per 100 g made thick or 71 made loose, purely as a function of how much water went in. Neither figure tells you anything about the oats.
What the mistake costs
Log 100 g of cooked rice against the dry figure and you have overstated the meal by 235 kcal. Log 100 g of dry rice against the cooked figure and you have understated it by the same.
Do either once a day for a week and the error is about 1,600 kcal — roughly a fifth of a kilo of fat, in the wrong direction, with nothing in the logging to show it. This is the most common reason a carefully tracked deficit does not match the scale, and it is far larger than any plausible error in the calorie figures themselves.
Which convention to use: weigh dry wherever you can. It is one weighing, before water is involved, and the number on the packet already refers to it. Weigh cooked when you are serving from a shared pot, and pick a database entry that says “cooked” — most apps have both, and the two entries are 180 kcal apart. Reading a food label covers how to tell which one a packet is quoting.
Ingredients, not meals
The second thing about this band: nobody eats 100 g of it.
Flour at 364 kcal per 100 g sounds like a food to avoid until you notice that a white sauce uses 30 g, which is 110 kcal across four servings. Sugar at 387 is the same arithmetic — two teaspoons in a coffee is 8 g and 32 kcal.
The band is a shopping list of ingredients, and ingredients get divided by the number of people eating. The exception is sugar in drinks, where 100 g arrives across a day without any effort at all: four regular soft drinks is 140 g of it.
Where per-100 g comparisons break down
Air-popped popcorn is the clean illustration. At 387 kcal per 100 g it sits beside flour and sugar in the table, which makes it sound like a dense food.
A hundred grams of popped corn is about three litres — a cinema bucket. A normal bowl is 20 to 25 g, which is 80 to 95 kcal, and it takes twenty minutes to eat.
Density per 100 g is the right comparison for foods of roughly similar bulk. Across foods whose volumes differ by a factor of fifty it stops meaning anything, which is the honest limit of the whole density ladder. What you actually need to know is what your portion weighs — and in this band, whether you weighed it before or after the water.
The rest of the ladder
Under 5 · under 10 · under 20 · under 30 · under 50 · under 100 · under 200 · under 300 · under 400 · under 500
Figures are typical values from USDA FoodData Central and product labels, and vary by variety, brand and preparation. General information, not medical advice.