Mac and cheese: three swaps, 81 fewer calories a serving.

Classic vs lighter, per serving.

The same mac and cheese, made two ways from the same library entries and the same 6 servings. The lighter version is the one built on the screens below.

Saturated fat comes from the same USDA entries; the recipe sheet itself shows calories, protein, carbs and fat. Calorie and macro figures are fitness estimates, not medical or dietary advice.

Swap by swap.

Each change in turn, from the classic to the lighter version, and what it does to one serving.

1. Use 1% milk instead of whole

−18 kcal, −2 g fat, −1.2 g saturated fat a serving

For the same 600 g of milk, 18 kcal and 2 g of fat less a serving. The cheese still carries the flavour.

2. Use reduced-fat cheddar

−33 kcal, +2 g protein, −5 g fat, −2.4 g saturated fat a serving

The same 225 g of cheese takes 33 kcal and 5 g of fat off a serving, and it melts into the sauce much as regular does.

3. Use 15 g of butter, not 40 g

−30 kcal, −3 g fat, −2.1 g saturated fat a serving

The flour needs only a little fat to cook into the sauce. The rest was 30 kcal a serving.

The sample data

These are the amounts of the lighter version used on the screens below, with each figure taken from the library entry for that ingredient. They are sample figures for a pot or tray of this size, not a measurement of anyone's kitchen.

Calorie and macro figures are fitness estimates, not medical or dietary advice. Ingredient values are from USDA FoodData Central, which is in the public domain.

Why this recipe

Mac and cheese is a good recipe to build because the sauce is only a few ingredients and each one moves the numbers a lot. A box or a restaurant bowl never tells you its cheese, milk or butter, and building your own gives you figures you can trust.

What to weigh

Weigh the pasta dry, as the library entry describes it. The sample finishes at about 1,600 g from 1,218 g of raw ingredients, because the pasta takes up water as it cooks. Water adds grams, not calories, so it lowers the calories per gram but not the calories in a serving.

How to cook it

The method for the lighter version above, using the amounts in the sample data. Use a food thermometer to check the safe temperatures.

1. Cook the pasta in salted boiling water until al dente, then drain.
2. Melt the butter over medium heat, stir in the flour and cook for 1 minute, then add the garlic for 30 seconds.
3. Whisk in the milk a little at a time and cook, stirring, for 5 to 6 minutes until it coats the back of a spoon.
4. Take the pan off the heat and stir in the cheese a handful at a time until smooth. Season with the paprika and a pinch of salt.
5. Fold in the pasta and serve straight away, or bake for 15 minutes at 375°F (190°C) for a browned top.

At a glance

• Prep: 10 minutes
• Cook: 25 minutes
• Makes 6 servings
• Per serving: 410 kcal, 22 g protein

Times are for a home kitchen and leave out any marinating or resting the steps mention.

Tips while you build it

• Weigh the pasta before it goes in the water. A cooked weight is not what the library row describes.
• Take the pan off the heat before the cheese goes in. Reduced-fat cheddar melts best gently, and a smooth sauce needs no extra butter.
• A serving is about 267 g, roughly a large bowl. Log by weight when you are measuring.

Go further

• Cooking for a crowd? Build the classic as a second recipe, with whole milk, regular cheddar and 40 g of butter, and log whichever one you served.
• Stir the cheese into the sauce in handfuls rather than all at once, so it melts evenly without a thickener.

Each change is a second recipe with its own name, so the first stays as you built it.