> Let people who are used to meat/dairy diets adopt plant-based diets and I wouldn't be surprised if this leads to more of them becoming overweight.
I think that the exact opposite is true. Most new vegans lose weight quickly.
There are no overweight fruitarians (imho - not my cup of tea). And not many vegans. But there are many ways how to do things - if you're eating a lot of fats, processed foods, junk food ... you'll be overweight, vegan or not.
Also, you can't replace meat/dairy with single protein source (e.g. tofu) and think that you're ok. That's not the way it works with the plants.
For me vegan diet means whole foods, minimum fats, as diverse diet as possible, almost no junk/processed food, 30-50% raw vegetables. It's not easy to gain weight this way.
> Imo it's a good thing when people try to eat less meat/dairy but they shouldn't think it's an easy thing to do that comes without caveats.
You're making it sound scary :) It is easy, certainly not hard, but you're right, new vegans have some things to learn.
The only supplement you'll certainly need is vitamin B12.
In the end what you'll want is fruits, vegetables and lentils of various kind. If you have a diverse diet, you'll have no problems.
Yes, it means trying (a lot of) new things and recipes and some learning (how to substitute meat/dairy with plant-based alternatives), but it's not hard and in the end it's very satisfying process. I'm always hunting for new recipes.
> David Raubenheimer is said to have conducted an experiment where people's behaviour showed that protein content is what disproportionately determines how much people eat until they feel saturated.
Yes, lentils & beans. Satiety guaranteed :)