Side-by-side differences between foods, varieties, formats and methods, with comparable data and the context needed to interpret it.
Almonds and pistachios are closer nutritionally than their reputations suggest. A roughly 1-ounce serving of either delivers about 6 grams of protein; almonds have a little more fiber, while pistachios come in a few calories lower.
Chicken breast is not the only high-protein part of the bird. Most cuts provide substantial protein, but fat changes much more. Skinless roasted breast is around 31 g protein and 3–4 g fat per 100 g; skin-on wings can approach 18–20 g fat.
The biggest difference between raw and cooked spinach is volume. One hundred grams raw is a large bowl; 100 g cooked is compact. Iron and calcium therefore look higher per 100 g after cooking, while vitamin C and folate can fall with heat and water. Boiling can also remove some soluble oxalate into the cooking water.
Simple and complex carbohydrates are mainly a chemistry distinction: simple carbohydrates are small sugars, while complex carbohydrates include longer chains such as starch and many fibers. They are not automatically “bad” and “good.” Whole fruit contains simple sugars along with fiber and micronutrients, while white bread and refined rice contain complex starch but relatively little fiber. Processing, fiber, the whole food and the amount of added sugar usually tell you more about nutritional quality.
Canning changes food but does not erase its nutritional value. Heat can reduce vitamin C and some B vitamins, while fiber, protein and minerals are generally retained much better. The biggest practical difference is often the packing medium: brine adds sodium, syrup adds sugar and oil adds calories.
Cooking tomato does not create lycopene, but it can make the pigment more bioavailable by disrupting cell walls and changing its physical form. Vitamin C and other heat-sensitive compounds can decline at the same time. Eating tomato with some fat, such as olive oil, also supports absorption of fat-soluble carotenoids.
Cooked carrots do not lose their main nutritional advantage. Beta-carotene remains and can become easier to absorb because heat softens the plant matrix. Fiber largely remains; some heat-sensitive vitamins can decline. Cooking may speed carbohydrate digestion, but a normal carrot serving still contains relatively little available carbohydrate.
Frozen fruit can be nutritionally very similar to fresh fruit. Fiber and minerals change little; vitamin C and other sensitive compounds may decline somewhat during processing or storage, but freezing then slows further deterioration. Fruit frozen soon after harvest can retain some nutrients as well as or better than fresh fruit stored for many days.
Frozen vegetables are not nutritionally second-rate. Blanching before freezing can reduce vitamin C and folate, but freezing then slows further loss. Fresh vegetables also lose sensitive vitamins during transport and refrigerator storage. Fiber, minerals and carotenoids are generally well retained in both forms.
Probiotics are live microorganisms that, when given in adequate amounts, confer a demonstrated health benefit. Prebiotics are substrates selectively used by host microorganisms that also confer a benefit. One is the microorganism; the other is material used by parts of the microbial community.
Glycemic index (GI) describes the response to a standardized carbohydrate amount; glycemic load (GL) also accounts for how much available carbohydrate is in the serving you actually eat. GL = GI × grams of available carbohydrate per serving ÷ 100. A high-GI food can therefore have low GL when the serving contains little carbohydrate.
Soluble fiber disperses in water, and some forms become viscous or highly fermentable; insoluble fiber retains more structure and contributes bulk. Oats, barley, legumes and fruit supply soluble fiber, while wheat bran, whole grains and many vegetables contribute more insoluble fiber. Most whole plant foods contain both.