Every food is a package of benefits and downsides, and almost no food is absolutely “healthy” or “unhealthy.” This section reviews hundreds of foods using a consistent method: nutrition facts per 100 grams, what the research really shows about the benefits, and the downside most articles skip.
How to read nutrition facts without falling into the traps
- Numbers on the label aren’t numbers in the body. Spinach contains an impressive amount of iron, but plant iron is absorbed at a rate of just a few percent. Bioavailability matters no less than quantity.
- “Per 100 grams” is misleading when the serving is different. Cinnamon and chia seeds look impressive per 100 grams, but the real serving is a teaspoon or a tablespoon.
- Processing changes everything. The same potato can be baked or fried French fries — a threefold difference in calories and a complete change in the fat profile.
- Nutrient density vs. calorie density. Walnuts are very rich in beneficial compounds and also in 650 calories per 100 grams. Both things are true at the same time.
The most popular topics on the site
| Question | Where to go |
|---|---|
| How much protein is in a food | Tuna · Lentils · Tofu · Peanut butter · Greek yogurt · Protein and nutrition facts in shrimp |
| Protein and carbohydrates in legumes | Chickpeas vs. hummus spread · Comparing red, green and black lentils |
| Benefits and downsides of seeds | Pumpkin seeds: downsides and serving size · Whole vs. hulled sesame |
| Fermented foods and probiotics | Kefir · Kimchi · Kombucha · Sourdough · Tempeh |
| Fats and omega-3 | Salmon · Sardines · Flax seeds · Olive oil |
| Antioxidants and polyphenols | Green tea · EGCG · Cacao and cacao nibs · Polyphenols · Dark chocolate |
| Gluten, celiac disease and grains | Gluten · Oats · Barley · Rye bread · Buckwheat · Quinoa |
| Processed food — what the real problem is | Ultra-processed food · Sausages · Sugary drinks · Artificial sweeteners |
“Healthy” foods have downsides too
This is the guiding principle of the site. Seaweed provides iodine in amounts that can overload the thyroid. Green tea blocks iron absorption. Kefir can cause digestive discomfort at first. Tuna accumulates mercury. Anyone who knows this side too makes better decisions than someone who only reads lists of “superfoods.”
For direct comparisons between similar foods see food comparisons, for information on vitamins, minerals and supplements see dietary supplements, and to see how these ingredients come together in a complete dish — recipes with a calorie estimate per serving.
Frequently asked questions
Question: What are nutrition facts? Answer: The amount of energy (calories) and macronutrients — protein, fat, carbohydrates and fiber — alongside vitamins and minerals, usually per 100 grams of the food. The figure that is almost always missing is bioavailability: how much of all this the body actually absorbs.
Question: How do you know how many calories are in a food? Answer: Calories are derived from the macronutrient composition — 4 calories per gram of protein or carbohydrate, 9 per gram of fat and 7 per gram of alcohol. That’s why fatty foods like nuts and oils are much more calorie-dense than water-rich foods like fruits and vegetables.
Question: Is there any food that is absolutely healthy? Answer: No. Every food also carries a downside — an iodine load in seaweed, mercury in predatory fish, phytic acid in legumes and whole grains, or simply high calorie density in nuts. What decides is the context: the amount, the frequency, and what else is in your diet.
Question: What’s the difference between processed food and ultra-processed food? Answer: Basic processing — grinding, fermenting, pasteurizing, freezing — is usually harmless and sometimes improves the food. Ultra-processed food is made of isolated industrial ingredients that don’t exist in a home kitchen, and is designed to be especially rewarding. The details are on the ultra-processed food page.
Question: How much protein do you need a day? Answer: The basic recommendation is 0.8 grams per kg of body weight, but that’s a minimum to prevent deficiency, not an optimum. For athletes, strength trainers and adults over 60, a range of 1.2-2.0 grams per kg is accepted. Especially rich sources: chicken breast, tuna, Greek yogurt, lentils and tofu.