That study you linked was done in animals, and I have a feeling it was dug up to support the notion that keto is in any way shape or form, good for you.
This study seems to focus on one variable, but there may be all sorts of bias in that those who consume a lot of saturated fat also have poor nutrition otherwise and lead unhealthier lives overall.
That might just be that together they are particularly palatable. You would have a hard job eating a bowl of sugar or a bowl of cream but mix them together and it's much easier.
I'm Over 40 and my body is showing it. I've done quite a lot of health research over the past few years. My personal metric at the moment is to lower my cholesterol and have been moderately successful without medication, so I think I'm doing something at least partially right.
I think the beneficial geeky rules of thumbs for healthy living that are simple rather than perfect, are:
1. One needs in ones diet 1.1 Protein 1.2 Fiber 1.3 Carbohydrates 1.4 Fats 1.5 Vitamins
2. Prefer foods with: 2.1 Unsaturated fats like olive oil, salmon, etc 2.2 Fibers
3. Generally avoid food with: 3.1 Fast sugars 3.2 High inflammatory index 3.3 High saturated fat content
4. Don't eat more than you consume.
5. For exercise, as the bare minimum, try to walk at least 8000 steps per day or equivalent. This will statistically reduce mortality considerably.
6. Sleep enough
7. Don't stress about the above rules! Pay attention, but don't judge - yourself or others.
8. Look into other stuff that's probably good for you like stretches, breathing exercises and strength exercises.
These are not hard and fast rules. But things that one can pay attention to, and through self observation perhaps make slow adjustments.
So don't stop eating burgers, but pay attention to the number of calories you eat, and of what the calories are composed of. Eat what you like, but don't delude yourself.
For geeks metrological devices may offer motivation. I have a bracelet that measures my steps and my sleep, and I feel it as a successful facilitation tool. But don't treat the device as a life coach, or the numbers as something that you should strive to optimize.
In my 20s I would eat ~1000 calorie meals with an entire pizza, salad, rich dressing, and a big slab of chocolate fudge cake. I was never slim, but I wasn't obese either.
If I tried that today I'd be breaking the scales in a few months.
Having to cut down on food a lot has been one of the hardest adjustments to make. Quite a few of my friends have never managed it and they're now dangerously beyond a reasonable weight.
However, it does also have an air of "this one trick will solve obesity!", which should be viewed with skepticism.
Going from three meals a day to a 16:8 eating pattern (16 hrs fasting, 8 hrs eating window) isn't too bad. It's basically skipping breakfast. Shortening the eating window until you're eating one meal a day is tougher. Then extending the fasting period > 24 hrs is tougher still. You can't just jump into this stuff while you're carb-addicted and your body is screaming for glucose. Getting used to a keto-style diet, even if your carb intake is just low but not keto-low, helps a lot.
I stand by that most people should be able to do it, as long as they can get over the hangry phase.
Check out these two things that come to mind, both cite an extensive list of studies:
Very quickly I'll go from eating a huge number of calories in a bulk phase, start cutting, and watch as over ~10-12 weeks as I need fewer calories each week to achieve a steady fat loss. After about 12 weeks of cutting fat I've gone from needing X calories to lose a pound a week, down to needing only 0.5X. At this point, I'm eating very few total calories. So I stop, and spend another 10-12 weeks slowly adding calories back in along with vigorous exercise until I'm gaining a steady half pound a week (maybe 50/50 fat/muscle). I'll rise up in weight about half of what was lost in the cutting phase, but ideally only about 1/4 of the fat lost. Once my total calories is back to a very high starting point, I'll start the cut again. This is the "secret weapon". I've lost a huge amount of body fat since starting this program, and my shoulders and legs are starting to stretch seams.
I came to this program after ~10 years of trial and error, but it works wonders.
If you need a starting point, Renaissance Periodization has some very expensive templates that can help a person get started with this. Or, just buy a scale, measure and weigh everything, and start cycling cut and bulk cycles every 10 weeks or so. Always aim for a pound lost a week, continuously dropping calories to maintain that rate, then bulk for 10 weeks, aiming to gain 0.5 pound a week along with strength training, adding calories each week to achieve that goal. Also, when cutting, long slow calorie burning like rucking, hiking, cycling, or swimming is perfect to help keep the daily calorie levels high. If not for those, I'd find my total daily intake to be unpleasantly low.