diet culture in the US really does tell us a lot about the state of biology and chemistry education in the US.
because anyone with a very basic understanding of how molecules work can see that pairing one molecule with a different type of molecule does not fundamentally change either one of them. for example, if you eat a piece of bread, no matter if it's white bread or wheat bread, your body is going to break both of them down into glucose. there is absolutely no debate about this. it becomes glucose, because that is what any type of carbohydrate becomes when humans digest it. glucose is just glucose, no matter where it came from. because if you changed any single thing about a glucose molecule...it wouldn't be glucose anymore, it would be something else.
the difference between white bread and wheat bread, especially whole wheat bread, is the addition of fibre. what the fibre will do is attach to the glucose molecule and make the body absorb it slower, which can have a host of effects on a person's body. those different effects are morally neutral, meaning one is not better than another. and when eating fibre, how it changes the way glucose is absorbed into the body isn't even the most important part! the most important part is that it helps keep digestion working well, which is a crucial part of the human act of eating!
[a quick and friendly reminder that adequate amounts of glucose are absolutely necessary to sustain a human life. no one is "built different," this is just a fact of human biochem.]
to use the carrot/ranch dressing example, because it is a good one for showing that ALL macronutrients are necessary, there are important vitamins that your body needs every single day, and they're called fat-soluble vitamins. they cannot absorb into your body in the presence of water, or protein, or glucose, or whatever else. they require fat to be absorbed properly and in correct amounts. they are vitamin a, vitamin d, vitamin e, and vitamin k. most of them support immune function and bone health, though each of them have other roles, as well. you don't want too much of any, but it is vitally important to get enough, and you will not absorb enough of any of them without a certain amount of fat in your diet. no amount of wishing or hoping or believing the lies about fat will change this fact.
so, back to carrots and ranch, they're a good source of vitamin a. but if you just eat a bunch of carrots raw, you're not going to be able to readily absorb all of that vitamin goodness because it must be paired with a fat. so ranch dressing, instead of being "unhealthy," is actually a great way to make sure you're getting all of the vitamin a you need (unless you'd like to go blind or have a terrible immune system and fragile bones), because the fat in the dressing will help your body absorb the vitamin itself. and it has the benefit of tasting good to a lot of people.
diet culture is so anti-science it's not even funny. it presents itself as this medical and scientific authority, when it is neither and often tries to force us to do the opposite of what is best for our bodies.
all for the profit of billionaires. and we hate billionaires, don't we? you gonna do the opposite of what's best for you because some billionaire doesn't care if you live or die so long as you make them just that much richer?
i say live just to spite them.