A habit already present at our table — lentil soup before the meal — and science has now given it a number.
The trial
A study (Flood & Rolls, 2007) on 60 normal-weight men and women who came to the laboratory for lunch once a week for five weeks, each week receiving one of four "preload" forms — broth and vegetables served separately, chunky vegetable soup, partly pureed, or fully pureed — or no preload, with the test meal fifteen minutes later[1].
The result
Consuming soup significantly reduced test meal intake and total meal energy compared with no soup — a reduction of 134 ± 25 calories, or 20%[1]. All four forms worked — meaning the form doesn't matter.
with soup
the same effect
Why does it work?
Because low-energy-density foods — heavy and bulky for their calories — produce more fullness per calorie than concentrated foods. Water bound inside food (as in vegetables, fruit and soup) lowers energy density and adds satiating volume far more effectively than water drunk separately[2].
This also explains why water before a meal works, but with a smaller effect (the article).
And salad too
Another study examined specifically the timing of salad consumption and its effect on meal energy[3] — the same rule: before the plate, not alongside it.
On our table
- Lentil or vegetable soup before lunch — traditional and effective.
- Green salad first before the kabsa, not beside it.
- At gatherings: start with soup and salad before the main dish arrives (majlis rules).
- Beware cream soups: high energy density — they cancel the benefit.