Calculating nutritional values
You calculate a recipe's nutritional values from the raw ingredients per 100 g, divided by the number of portions – cooking changes the weight, not the energy.
Ausführlich erklärt
The calories in a home-cooked dish aren't printed on any packet – but you can work them out fairly accurately in five minutes. The principle: weigh all the ingredients raw, look up the nutritional values per 100 grams (on the packet, in a nutrition table or in the Bundeslebensmittelschlüssel, Germany's official food composition database), scale them up, add everything together and divide by the number of portions.
An example for four portions: 320 grams of dry wholewheat pasta (about 1,100 kcal), 500 grams of lean minced beef (about 900 kcal), 800 grams of passata (about 200 kcal), 2 tablespoons of olive oil (about 180 kcal), onions and spices (about 40 kcal). That's around 2,420 kcal in total; divided by four, it comes to about 605 kcal per portion. Macronutrients work the same way: add up the protein, carbohydrates and fat for each ingredient.
The typical pitfalls: water has no calories, but it does have weight. Pasta doubles its weight when cooked, rice triples it, and meat loses about a quarter. So always calculate with the raw weight or with the values for “cooked” – never mix the two. Oil for frying counts in full, even if it was “just a splash”. When deep-frying, the food also soaks up extra fat that you haven't weighed. And a “portion” is only as accurate as your sharing out: if you divide a pot meant for four between three plates, each person eats a third more.
How accurate is all this? Under the EU guidance on nutrition labelling tolerances, even the values on packaging may deviate by up to 20% for fat, protein and carbohydrates, and the body uses the energy from fibre or resistant starch differently. Plus or minus 10 to 15% is realistic – perfectly adequate for weight loss, because what matters is the trend over weeks, not the individual meal.
Important for families: children don't need calorie counting – they need good food on offer. If you count at all, count for yourself – and stop as soon as you have a feel for your regular dishes. If you notice that counting is becoming compulsive or making you anxious about food, please get support, for example from the eating disorders helpline of the German Federal Institute for Public Health (BIÖG, formerly BZgA) on 0221 892031.