We are a commune of inquiring, skeptical, politically centrist, capitalist, anglophile, traditionalist New England Yankee humans, humanoids, and animals with many interests beyond and above politics. Each of us has had a high-school education (or GED), but all had ADD so didn't pay attention very well, especially the dogs. Each one of us does "try my best to be just like I am," and none of us enjoys working for others, including for Maggie, from whom we receive neither a nickel nor a dime. Freedom from nags, cranks, government, do-gooders, control-freaks and idiots is all that we ask for.
The old idea of the virtue of a low-fat diet is in the dustbin of history. There is no correlation between dietary fats and heart disease. However, there is a high correlation between being overweight and heart disease - especially "pear-shape" (abdominal) fat. Indeed, being overweight or fat correlates with many diseases: heart disease, high blood pressure, diabetes, several cancers including breast cancer, arterial disease, joint ailments and arthritis, Alzheimer's - the list goes on and on. Humans were not designed for dietary abundance, but for caloric scarcity.
That is about dietary fat. If you are concerned about hyperlipidemia, let your doc treat it if it concerns you. There are many alternatives for that.
To lose body fat, only a low carb diet works. Your body converts all carbs to sugar and then stores the excess sugar as fat. Dietary fat doesn't make people fat. Everybody knows what carbs are: sweets, fruits, dessert, root vegetables, juices, beer, grains, grain products eg pasta and bread, beans, corn, etc. The comfort foods.
To gain or maintain weight, eat plenty of everything including apple pie, ice cream, beer, Big Macs - and 70-100 gms of protein daily if you do heavy exercise (eg weights).
Can you lose weight with an hour of daily exercise? It depends on the intensity of that hour, but it's not a realistic effect for most. Still, it is worth doing for countless other good reasons including mental well-being and energy. Intense exercise tends to reduce appetite, so there's that too.
There are many diets, some more effective than others, but most will work to some extent. IMHO the best diet is to simply eat less. Not eat only proteins or not eliminate carbs. Just eat less until you reach the desired weight. There is no magic and the whole process is complicated by the fact that individuals are different and some have medical conditions that are difficult to overcome.
The point is that sugar is the preferred fuel of your body. Low carb always leads (eventually) to high stress hormones and impaired metabolism. Read the work of Ray Peat. Taubes will screw you up big time. I find it very easy to stay lean on high carb, moderately high lean protein, and very low fat.
If I take in more calories than I burn, I will gain weight. If I take in fewer calories than I burn, I will lose weight. It doesn't matter if the caloric deficit or surplus is carbohydrates or fat or protein or any combination.
Eliminate all carbs from your diet but run a caloric surplus, and you will still add weight. Period.
People who pay attention to carbs lose weight because they unintentionally cut calories without knowing it.