300 calories ANY day is extremely unhealthy. That’s literally a serving of oatmeal, yogurt, and an orange (a small breakfast). Someone trying to lose weight can eat as low as 1200 calories a day. A person cannot thrive, be active, and accomplish their goals if they don’t have energy. I hope the models you’ve met are doing well and not putting such a burden on themselves anymore.
I believe that for weight loss, it’s most effective and least stressful if you learn to just switch your carbs, eat more protein, and limit fats. For example, instead of rice, try using vegetables like cauliflower & squash or whole grains like quinoa. It’s good to eat small amounts of fats from fish, almond milk, and small servings of nuts.
I would imagine that models would have to eat limited to moderate amounts on top of their naturally thin frame to be fashion-fit. But look! Alexander Wang gives cheese out backstage to his models!
The diets of fashion models and elite female athletes are hard to look up. Does anyone know what/how much a typical runway model or serious college/professional long distance runner eats in a day?