I work in law, so I know how easy it is to find evidence to support whatever it is we want to prove to ourselves and others.
So I recommend throwing away the books, keeping an open mind and listening to your body, not the "experts."
Exercise does make a difference with weight loss -- certainly in my experience it does! when I ran, I could eat whatever I wanted and kept 30 pounds off with ease for years! when I didn't exercise, I was
always chubbier! -- but even exercise experts agree that 80 percent of weight loss success comes from diminishing how many reps you do with your fork, not increasing how many reps you do with weights. It's industry standard nowadays for fitness buffs to say that most results come from the kitchen, not the gym.
Also, I think it's just as wrong to dismiss exercise just as it is to rely too heavily on it. The answer is somewhere in the middle. Exercise helps the body in a number of ways, not just relating to weight loss. Many use it to manage hormones/diabetes/stress/depression. Exercise becomes more imperative as we get older, not optional as it is when we are younger. Most people would like to be able to lift themselves from the toilet when they are elderly. Exercise supports that goal. Non-exercise doesn't.
There are lots of thin people who restrict calories/carbs and never exercise. My mother is an example of that. She gained 100 pounds by her fourth child, lost it through low carb in the late sixties - while giving herself a small daily treat each day - and never gained it back. She also never exercised if she could help it. LOL.)
However, if a more toned aesthetic is the goal, that will only happen with exercise.
So I'd recommend throwing away the books and just experimenting with your own body. Some people do a lot better with steady state cardio (long, easy walks) than with HIIT training while others have experienced the opposite.....
Also, keep in mind that lots of stuff passed around as gospel in the 90's by the "experts" (low-fat, etc.) is being discredited today. "Experts" ordered my grandfather to use margarine rather than butter after open-heart surgery in the 70's and now we know how lethal that is ... The "experts" say I should weigh 115, but my periods always stop when I go below 125. (When I weighed 115 for 3 years, they stopped completely. No "expert" made the connection to my low weight because I fell within the "perfect" chart range.) I now weigh 142, which shocks most people because I look much smaller. I look smaller because I weight train. Weight training tightens everything up and makes us look smaller and causes things to get looser, even if the scale goes up (because muscle weighs more).
Anyway, everything in moderation, including exercise & books by people with fancy initials!