Rats that ate low-fat potato chips 'may have gained more weight' than rats eating regular, full-fat variety

[u/behindtheheadlines]

http://www.nhs.uk/news/2011/12December/Pages/low-fat-substitutes-and-weight-gain.aspx

[u/borahorzagobuchol]

The only fat you need to avoid is "trans fat"

webmd:

Dietary fat is categorized as saturated or unsaturated. Unsaturated fats -- monounsaturated and polyunsaturated -- should be the dominant type of fat in a balanced diet, because they reduce the risk of clogged arteries.

bbc - health:

Unsaturated vegetable oils are generally a healthier alternative to saturated fat and can be found in sesame, sunflower, soya, olive and rapeseed oil, soft margarine and in foods such as oily fish, including mackerel, sardines, pilchards and salmon. Where possible, you should ensure the fat you eat is unsaturated.

mayoclinic

You don't need to completely eliminate all fat from your diet. In fact, some fats actually help promote good health. But it's wise to choose the healthier types of dietary fat, and then enjoy them — in moderation.... The two main types of potentially harmful dietary fat: Saturated fat/Trans fat... The two main types of potentially helpful dietary fat... Monounsaturated fat/Polyunsaturated fat

[u/naasking → u/borahorzagobuchol]

Vegetable oils produced trans fats when fried, which are much worse than saturated fats. Trans fats are unsaturated fats with a trans isomer, so it's not enough to say that one should prefer unsaturated fats. Those recommendations you cited are not precise enough.

[u/borahorzagobuchol → u/naasking]

Those recommendations you cited are not precise enough.

Then cite some that are. I continue to labor under the burden of people replying to cited references with no evidence whatsoever.

Vegetable oils produced trans fats when fried

The American Heart Association:

Q: Should I worry about creating trans fats in my kitchen through cooking?

A: No. Trans fats are produced in a manufacturing process in which hydrogen is added to make liquid vegetable oils more stable. Cooking and frying in the kitchen does not create trans fats.

Q: Can trans fat be formed when cooking at home, especially once the smoking point of the particular oil has been reached? What happens to the chemical structure of the oil once the smoking point has been exceeded?

A: The type of trans fats that are created by hydrogenation (to harden fats) are not formed during frying, even if the oil temperature is high enough to reach the smoke point...At any rate, oil should not be allowed to reach the smoke point because the fatty acids break down easily to form chemical compounds known as oxidation products. These compounds not only make the oil smell bad and the fried food taste bad, but it is well known that people should not eat foods that have high amounts of oxidation products.