I mean, it really depends on the details. I didn't exactly claim these were balanced meals, and honestly I don't think cheese has a significant negative impact on people. But we're comparing it to what the person probably used to eat, to heavy-carb foods (especially "salads" such as potato salad), and to foods that lack nutrition. These salads have a lot of nutrition and not a lot of carbs. Salt and the worse fats are probably the biggest problem here.
People need salt. If you don’t eat salt, your body can’t retain water or conduct nerve signals. If you’re chronically dehydrated and unable to conduct nerve signals, your life sucks.
Eating 2/3 of a plate generally speaking isn’t a bad idea, and dietary science has advanced since the 1980s to the point where we now know the body can produce fat from dietary intakes other than actual fat.
In fact, a high fat, low carb diet like a plate of 2/3 meat and cheese plus some veggies, is a great way to improve one’s gut biome.
My own anxiety and depression basically disappear when I keep my carb intake below 120 grams a day.