Easier to understand does not mean simpler to solve.

40% of the U.S. is overweight, 11% are diabetic, etc etc. There is no such magnitude of a problem due to erythritol or artificial sweeteners.

If "too many calories" were easy to solve we would not have an epidemic of it.

No, the GP is correct. The solution is simple. Calculate your daily passive calorie requirement, take in less calories and/or up active calorie requirement. Simple.

Now, implementing this is hard or maybe impossible for many individuals, I'm not denying this. The solution is simple, but for some it is not easy to implement.

This is word play on the meaning of word simple in "simple solution" that can mean both easy to do or easy to understand. This is orthogonal to the point being made.

It is simple as in you know if its a problem for you or not. Most people can eat sugar without becoming fat.

Yup. If more calories were a "simple problem to solve", how come it isn't solved?

It is a simple problem to solve. Eat less, exercise more. Tons of people have done it successfully. Tons of people do it without even thinking about it.

It’s just that some people have mental addictions or whatever problems that makes them want to overeat or not exercise enough. But the solution itself is simple and straightforward.

If the "tons of people" in the first paragraph were multiples more than the "some people" in the second paragraph, then I would agree that the solution is simple. But the thing you describe in the second paragraph is what makes actually solving obesity hard. Using artificial sweeteners is one of the ways in countering the latter half of the puzzle.

Fair enough. To me, simple and easy are not the same thing. Chess is a simple game that's not easy to play. In the same vein, to me, "take in less calories than you burn" is a simple concept, but not easy to do. It doesn't make the concept wrong, though.

"primitive solution"

One problem is that for some people, the daily calories used by the body lowers when you reduce the calories intake (mostly by adjusting NEAT). So for some people it's harder to lose weight than for others.

While this looks simple on the surface, what I've found is that there's a missing component to what you describe: the effect sugar has on the perception of satiety: when I eat sugar, I always have a hunger-like feeling, which incites me to keep on eating. I don't get this with sweeteners.

This happens with sugary drinks, but also with solid food, such as cake.

Sure, once you see your weight go up, you can adjust. But adjusting is difficult, and I think this is a contributing factor to the weight problems people have.

That's because not enough of the hormone leptin (feeling of satiety) gets created when you ingest sugary foods.

I've noticed this happens even after desert. If I have a steak or similar and end there, it's fine. If I have something sweet, I'll feel hungry in two hours.

> "Too many calories" is a simpler problem to solve: increase physical activity, take less sugar, or take sugar less frequently.

From Taubes' Good Calories, Bad Calories:

> “To attribute obesity to ‘overeating,’” as the Harvard nutritionist Jean Mayer suggested back in 1968, “is as meaningful as to account for alcoholism by ascribing it to ‘overdrinking.’”

Obesity etc are hormonal issues. It is not simple calorie-in, calorie-out math. I have been on a diet, off-and-on, for 15 years, and I can notice craving for carbs increase after "slipping/cheating" by consuming sugary food. While I generally manage to avoid reaching for snacks, I can only imagine how people can struggle with this, more so when others around them are stuffing themselves with food rich in sugar.

For me, it's calories-in calories-out. I've been counting calories for two decades and learned a couple things about my particular case:

- If I consume more than 2,300 kcal per day, I gain measurable weight in weeks.

- If I consume less than 2,100 kcal per day, I lose measurable weight in weeks.

- Physical activity has little effect on my weight change.

- Age has little effect on my weight change.

- When losing weight, I must work out to retain strength. Moving around an extra 10 kg takes strength that is lost when the weight is lost.

In my case, any hormonal effects are secondary to the above. I've changed what I eat over the years and my weight didn't change if I consumed the same kcals. There are likely subtleties I am missing, but eating less works for me. YMMV

What do you eat in those extra 200 calories?

I sometimes binge on cheese and nuts or peanut butter when I'm not at my best, but even when I do this for weeks, and I'm talking an extra 2000 calories in a day which is easy with those things, I haven't gained weight (fat). I don't feel as good and I don't recommend it, but I think it's safer than eating sugar if one is going to binge. I had a couple years 10 years ago where I ate sweet things most days and did gain noticeable weight (fat). So it's not like I'm genetically not going to gain weight either.

As an aside, physical activity might not affect weight change as much but it will affect the fat/muscle ratio.

You are very lucky to be able to eat like that without weight gain!

The extra 200 calories would be more of the same, just bigger portions. I record everything by weight when eating at home, and have a good feel for calories per unit weight, but double check often. Cheeses are about 100 cals per oz, breads or snacks with little fat (pretzels) are 80-100 cals per oz, nuts are dangerously calorific at 160-180 cal per oz. Peanut butter is the same. I eat nearly everything, both good and bad for me, but keep track of calories and it's been working for me. I do eat ice cream occasionally, with full awareness of how much. My calorie limit is a target, but I enjoy life. The only thing I've eliminated completely is alcohol.

Sugar, carbs in general, is particularly problematic.

I know of diabetics who cannot give up on sugary treats with full knowledge of the consequences of their behavior, people who have seen others in the family lose eyes, limbs, kidneys and life to the disease. Not a single one of them will consume a block of cheese or butter if one were to set these in front of them. Or a plate of diced carrots or cucumbers. It is always the chocolates and chips and the cookies and the ice cream and the biscuits.

Over the last two decades, I have been 128 kg at my peak. I have also been 93 kg. I have noticed that carbs absolutely wreck my ability to maintain weight. You lose the will to say no to food.

I am in India. Festivals start in September and continue for the next few months. It is an unending caravan of carb-heavy food. I can very easily put on 10 kg in those months. 70K excess calories in 2-3 months is not a lot. This does not happen with high fat food, because you cannot eat those in large quantities. They have high satiety value.

> Physical activity has little effect on my weight change

The human body is insanely adaptive. The natural impulse, I believe, is to conserve energy. For different people, it will respond to continuous over- and under-eating as well as over- and under-exertion in different ways.

People should do what works for them.

> For me, it's calories-in calories-out.

> Physical activity has little effect on my weight change.

Those two statements appear to be contradictory?

It means how much I eat has a much larger effect than physical activity. I can eat more calories in 5 minutes than I can work off in two hours of brisk walking.

I'm quite convinced humans, unless in an environment that restrict their food intake (e.g. being working outside in the fields), are just generally not able to manage the hunger of the sugar-induced insulin crash.

I've switched to the keto diet for other health reasons --I never had any weight issues, and my weight didn't change-- but I never feel as hungry as I used to. But eat a square of chocolate and the hunger comes back.