I think this has a real answer, thus it is not is Cafe Society.
Many plants are minimally processed by our bodies. They go in, nutrients are extracted, and (typically) a large percentage of their mass is excreted. On the other hand, meats and fatty materials take longer to effectively digest.
I once visited France and was exposed to the custom of eating the salad after the meal. It was explained to me that eating veggies after the meal helped push the meal out of the body.
Now lets go with a hypothetical.
I’m at a restaurant at dinner. I want a top sirloin medium. Dinner comes with an excellent salad and garlic bread. As is usual in U.S. restaurants, the salad will come before the entree (meat and potato in this case).
The question: If I eat the salad after the main meal will I receive LESS calories because the veggies will tend to force my digestive tract to push the meaty portion through earlier?
By the time anything is “pushed”, it’s all mixed together in your stomach. I think the difference between before and after salad is exaggerated. Food remains in your stomach longer than you seem to think.
No. This is absurd. Under any normal situation the food will remain in your digestive system for 24 to 96 hours, plenty of time for near-complete breakdown into fatty acids, amino acids, and simple sugars, the only things that are digestible. (Nitpickers: vitamins and minerals are absorbed rather than digested, since they do not need to be broken down.) Nothing about your intestines was designed to process foods in certain orders.
Eating salad first might have other effects. It might fill you up so you eat less of the entree. It might interfere with the taste of other foods. It might encourage you to have more dessert to compensate. But none of those things are happening in the small and large intestines.
And you - and also the French if they believe it - are also wrong if you think meat and vegetables take different total times to digest. They do not.
I am not a nutritionist, but if I understand correctly, the body digests the food for as long as it has to. The veggies don’t speed up the meat - the meat slows down the veggies. In other words, the salad doesn’t help.
Now…please note that I said “believe” and that I am flabbergasted myself to hear such a mechanistic explanation from herbalists. Generally they’re much more vague and handwavy than that. But I’ve heard it hundreds of times, from different herbalists from different countries. It’s a very widespread belief. Some countries achieve this through salad greens, others by “apertifs” - bitter herbs in booze…in the US, we tend to do it with coffee.
I also have no farking clue if any of it is true. It’s something I’ve been trying to chase down and vet for over a decade. I cannot fathom why bitters - which rarely come with high fat food - would trigger the release of a chemical needed to digest fats. But I will also admit that my belly feels less full after bitters. Is the “bitter–> bile” mechanism correct? I dunno. Do bitter things help my subjective sense of digestion? You betcha.
But no, it won’t push things through substantially quicker. It just relieves the feel of bloat from overindulgence. Meat and veg take about the same time to digest, anyway.