How do nutritionists and dietitians know...?

Question

... exactly how many calories/ fat/ carbohydrates there are in food? I mean, if you go to a restaurant for a burger, it just seems there's so many more calories and fat in it than if you make a replica at home! Like, a burger at McDonalds may be around 800 calories, but if you make it the same at home, it could be around 500. So how do they know?

Answer 1

Calories are a unit of heat energy. Actually one calorie is is a kilo calorie, which is 1000 calories in scientific terms. The calorie is a unit of heat, to measure it you measure how much the temperature changes in a known quantity of water when the item is burned, so they burn food to find out how many calories are in it.

Answer 2

Well if you make it at home you have more choice!

For one, you chose the meat cut (and you can chose a very lean one, cutting on fats immensely).

Then, you can chose which oil to fry it into, and you can use healthier alternatives than palm/coconut oil (norm).

On top of that, you can drain, rinse and pat dry (which takes a way a considerable amount of fat.

Finally, you can eat it with multigrain whole bread and lowfat mayo, again reducing the calories.

So yes, unless you make them the same way McD does, hamburgers at home can be considerably lower in fats IF you make smart choices.

Answer 3

I think is it some guess work but also from past experience and the results they get. And their are plenty of labs for testing these things. Of course, for each person it is a little different and that can't be changed.

Answer 4

you aren't supposed to be eating foods that aren't cooked at home just because of that reason. unless you prepare the food yourself the nutritional and caloric content will always be questionable.

Answer 5

not guesswork. calories are accurately measured using calorimeters.