Most low-carb advice boils down to one question: what do you put on the plate instead of the bread, rice, pasta and potatoes? Carbohydrate (carbs) is the starch and sugar in food. Staples like these carry a lot of it in a normal portion, so swapping them is the quickest way to see how a day changes.
Official guidance for adults in Europe puts carbs at roughly 45–60% of daily energy. Low-carb eating deliberately sits below that. Definitions vary from source to source, but many describe "low-carb" as under about 130 g a day and "very low-carb" (keto) as under about 50 g. Don't treat these as exact lines.
A few typical portions show why staples matter so much. Cooked white rice has about 29 g of carbs per 100 g, so a 150 g serving is around 43 g. Cauliflower has about 5 g per 100 g. The same weight of cauliflower "rice" therefore carries a fraction of the carbs, though it also has far less energy and is much less filling.
A swap cuts carbs fast, but it is a trade, not a free win: you also lose some fibre, energy and fullness unless the replacement is chosen well.
Good swaps keep the plate satisfying. Vegetables like cauliflower, courgette, cabbage and mushrooms bring fibre and volume. Eggs, fish, yoghurt, nuts and olive oil add protein and fat so you aren't hungry an hour later. Swapping white bread for a low-carb "bread" that is mostly refined starch with a different label doesn't help much, so check the label for carbs per 100 g.
Watch what leaves the plate too. Beans, lentils, oats and whole grains are carb-rich but also the best sources of fibre, and EFSA considers about 25 g of fibre a day adequate for adults. If your swaps remove all of them, plan fibre from vegetables, seeds and berries.
Low-carb diets can help some people eat more satisfying meals, and some find them easier to stick to. But when research compares them with balanced-carb diets for people who are overweight, a large Cochrane review found little to no difference in weight loss at one to two years, averaging under 1 kg. Blood pressure and cholesterol markers were also similar. Results vary person to person, and trials beyond two years are scarce. The best plan is the one you can keep up while still eating a wide range of foods.
This guide is information, not medical advice. If you have a health condition, are pregnant or breastfeeding, have or have had an eating disorder, or take medication, especially for diabetes or blood pressure, talk to a doctor or dietitian before cutting carbs. Medication doses can need to change when your food does. Low-carb is also not a quick fix, and nobody should eat below the minimum energy intakes public health bodies recommend.