Side-by-side differences between foods, varieties, formats and methods, with comparable data and the context needed to interpret it.
Cooked white and brown rice are much closer in calories, carbohydrate and protein than they are often made to sound. The important difference is structural: brown rice keeps the bran and germ, so it provides roughly 1.5–2 grams of fiber per 100 grams versus less than 1 gram in white rice and usually substantially more magnesium and other micronutrients.
At the same cooked weight, potato usually provides fewer calories and carbohydrates than white rice: roughly 90–95 calories and 21 grams of carbohydrate per 100 grams versus about 130 calories and 28 grams. Water explains most of the difference. In a real meal, however, a large potato and a smaller rice serving can end up with almost the same calories.
Potatoes and sweet potatoes are much closer in calories and carbohydrate than their reputations suggest: both are around 90 calories and 20–21 grams of carbohydrate per 100 grams cooked. The interesting difference is micronutrients: orange sweet potato stands out for beta-carotene, while potato often provides more potassium and vitamin C.
Plain Greek yogurt usually contains about twice as much protein as conventional plain yogurt, roughly 8–10 grams versus 3–5 grams per 100 grams. But “Greek” does not automatically mean more fat or less sugar: those depend on milkfat level, processing and whether sweeteners were added.
Red and white meat can provide almost the same amount of protein when lean cuts are compared. Red meat—beef, pork and lamb—usually provides more heme iron and vitamin B12, while white meat such as poultry can be leaner in cuts like breast. For fat and calories, the cut, skin and processing matter more than the color category.
Tuna and salmon are two very different ways to get protein. Per 100 grams cooked, yellowfin tuna has roughly 29 grams of protein and 130 calories, while Atlantic salmon is closer to 22 grams and 200–210 calories. Salmon's advantage shows up elsewhere: it provides far more EPA and DHA. Mercury in tuna also depends heavily on the species.
Canned sardines and tuna can both provide roughly 24–26 grams of protein per 100 grams, so protein is basically a tie. The difference appears in the rest of the package: sardines provide far more EPA and DHA, can add substantial calcium when the bones are eaten and average very low mercury. Tuna mercury varies by species.
Lean white fish often falls around 80–130 calories per 100 grams cooked, while many oily fish reach 180–250 because they contain more fat. That same fat explains their large advantage in EPA and DHA. Protein is much closer than the labels suggest: both groups commonly provide roughly 18–25 grams per 100 grams.
Cooked skinless chicken breast is leaner and more protein-dense, at roughly 31 g of protein and 165 calories per 100 g versus about 26 g and 209 calories in skinless thigh. Thigh contains more fat and is generally more forgiving and juicy; keeping the skin widens the gap.
Cooked skinless chicken and turkey breast both provide roughly 29–31 grams of protein per 100 grams. Turkey breast can be a little leaner and lower in calories, but the difference between breast, thigh and skin-on meat is larger than the difference between the two birds.
Lean beef and lean pork can provide very similar amounts of protein. Beef usually supplies more iron and vitamin B12, while pork is notably rich in thiamin. For fat and calories, the specific cut matters more than whether the meat came from cattle or pigs.
Cooked lentils, chickpeas and beans are more alike than their reputations suggest: all provide roughly 8–9 grams of protein per 100 grams. Chickpeas are more calorie-dense, lentils tend to edge higher in iron, and bean values vary by type.