Most of all they are cutting down on total calories. It seems that for most people total calories are more important than the carbohydrate/fat-ratio.

>It seems that for most people total calories are more important than the carbohydrate/fat-ratio.

It's also relatively easier to track. It's easy to say "Well, I can consume about 2000 calories per day, this donut has about 300 so I'll have roughly 1700 calories left", but it's quite difficult to know the breakdown of how much carbs/protein/fat should be consumed within those 2000 calories and more difficult again to plan and monitor for those values.

> [Total calorie intake] is also relatively easier to track [than carb/fat ratio].

I'm not sure about that...knowing total calories is not quite that simple (without fairly-sized error bars), due to differences in basal metabolic rate, efficiency of absorption of calories, determining calorie counts in general (particularly for restaurant food), etc etc.

On the flipside, it's much easier to understand the level of fats and carbs in a given item of food; hell once you start paying attention, you can even get a good rough guess just by the taste. On top of that, your body gives you some pretty nuanced signals related to hunger: without having put in any extra research or effort, I can definitely tell when I'm hungry for protein/fats vs carbs. I doubt it's just me, but IME at least, the feelings are completely different (this is also supported to some degree by nutritional science, in that protein and fats are known to provide satiety in a way that carbs don't).

> due to differences in basal metabolic rate

Not relevant to calorie intake (relevant to calorie expenditure, which is a different issue.)

> efficiency of absorption of calories

differences here are the aggregate of differences in the efficiency of absorption of particular nutrients, so while this is a real source of challenges in measuring total calorie intake, its also a challenge in measuring carb/fat ratio of intake.

> determining calorie counts in general (particularly for restaurant food)

Again, the same problem with calorie counts here applies to carb/fat ratios.

>Not relevant to calorie intake (relevant to calorie expenditure, which is a different issue.)

What? How in gods name would you determine the appropriate amount of calories without having a sense of expenditure?

> differences here are the aggregate of differences in the efficiency of absorption of particular nutrients, so while this is a real source of challenges in measuring total calorie intake, its also a challenge in measuring carb/fat ratio of intake.

The variance (across time) of the ratio of absorption of fats vs calories is presumably much lower than that of calories in general (the latter is MUCH more sensitive to both lifestyle and things like "I happened to walk s lot this week"). That's partly conjecture though and your point in general is sound.

> Again, the same problem with calorie counts here applies to carb/fat ratios.

Come on man,the only part of my comment you didn't address is the one that talks in detail about the differences in difficulty between calorie estimation and macronutrient makeup estimation. Why pretend to respond if you're going to ignore the half of my comment that directly addresses your disagreement?