Salad before a meal

A salad before a meal helps if it’s big and light. At Penn State, a large light salad cut the whole lunch by 12%, and the same size bowl made rich with more dressing and cheese raised it by 17%. In a small study, eating the vegetables and protein before the bread also left blood sugar lower an hour later.

Why “start with a salad” is only half right

“Have a salad first and you’ll eat less” is a common piece of diet advice. It’s half right, and which half you get depends on what’s in the bowl. A side salad with croutons, cheese and a pour of creamy dressing can carry as many calories as a small meal, and it doesn’t make you eat that much less of the main.

The Penn State lunches

Barbara Rolls’s lab at Penn State tested this in 2004. 42 women came in for lunch once a week for seven weeks. On six of those days lunch started with a salad they had to finish, and on one it didn’t. Then came pasta, and they could eat as much of it as they wanted.

The salads came in two sizes, 150 g or 300 g, and three levels of richness, 0.33, 0.67 or 1.33 calories per gram. The researchers changed the richness by “changing the amount and type of dressing and cheese”.

The calories are the salads’ weight times their richness. The whole lunch means the salad and the pasta together.

The large light salad and the large rich salad were the same size bowl. One made lunch smaller and the other made it bigger, and the difference came from what went on top.

How it works

Calories per gram has a name, energy density. Romaine is about 0.14 calories a gram and olive oil about 8.5, so a bowl’s energy density depends mostly on how much dressing and cheese is in it.

The light salad took up room for very few calories, and the women ate less pasta after it. The rich salad took up the same room with four times the calories, and they didn’t eat enough less pasta to make up for it.

It works like a coupon or a surcharge. A big, light starter is a coupon for about 12% off the meal. A big, rich one is a 17% surcharge, even though it looks like the same bowl.

What a light starter looks like

Here are some starters from the bowl builder’s food tables, placed next to the trial’s salads.

The usual side salad with ranch lands in the middle, where the published summary has no result. The ranch is 78% of its calories. Swap it for a teaspoon of oil with vinegar and it moves to the light end. The caesar, at about 1.8 calories per gram, is richer than anything the trial served. Starter or meal places your own bowl next to the trial’s salads.

Salad first and blood sugar

A second reason to eat the salad first is blood sugar. In a 2015 study, 11 adults with type 2 diabetes on metformin ate the same 628 calorie meal twice, a week apart. It was ciabatta and orange juice, grilled chicken, a lettuce and tomato salad with low-fat Italian dressing, and broccoli with butter.

One week they ate the bread and juice first and the rest 15 minutes later. The other week they ate the chicken and vegetables first and the bread and juice 15 minutes later. With the vegetables and protein first, their blood sugar was 28.6% lower at 30 minutes, about 37% lower at an hour and 16.8% lower at two hours, and their insulin was about half at an hour.

It was one meal in 11 people, and the salad came with the chicken, so it doesn’t tell you what the salad did on its own. But it costs nothing to try. meals.guide has a calculator for eating your plate in that order.

The best case against salad first

“The women had to finish the salad, and it was one lunch. In real life you’d skip the salad, or eat more at dinner.” That’s fair. The trial measured single lunches in a lab, with a salad nobody could leave. It didn’t follow people for weeks to see if they made up the calories later.

The longer evidence points the same way. In a year-long trial from the same Penn State lab, women told to eat more water-rich foods, mostly vegetables and fruit, alongside less fat lost about 17 pounds (7.9 kg), against about 14 (6.4 kg) for women told only to cut fat. They said they were less hungry, and they ate a greater weight of food. Salad and weight loss has the details.