Americans are among the heaviest due to High Fructose corn syrup being in almost EVERYTHING. Outside of the US even many of the exact same branded products will not contain HFCS as health regulations will not allow it. Canadians have almost identical diets to the US and the obesity rate is significantly lower. Same for the UK.

Every country except the US doesn't have a Corn lobby forcing corn to be used as a sweetener and to make ethanol for no logical reason.

Australia is known to have larger meal portions than the US in general and their obesity rate is over 30% less.

If someone consistently eats a processed food diet, corn syrup is not their only problem.

A no carb or low carb diet works because one is consuming less calories each day as compared to what was consumed before dieting.
I can start a fad diet that allows you to eat a candy bar, twice a day, and people will lose weight. Not because candy bars are a miracle food. Loss of weight would occur because the person on the diet is consuming fewer calories. Less food (calories) consumed daily is the ONLY reason fad diets work.

There is one incredible miracle that fad diets create. The person(s) or company pushing the diet earns millions of dollars each year. The potential to become rich is the reason fad diets are created.

Eat meat and fresh veg, fruit, beans, grains, etc.in moderation, with a nice glass of wine, or a good ale, also drink plenty of water, and you will be fine.
Get plenty of exercise.
Putting on a few pounds? Cut down on food portions. (Not the Ale!)
Avoid all processed food.
Simple.

As humans we are inclined to ignore science and logic when it does not validate our preferred habits or lifestyle choices. If we were designed to eat meat then we would not have to cook it and would have teeth like a lion or tiger.

The literature found in pubmed.gov is overwhelming that whole food plant based diet is by far the healthiest option. There are no long term studies to validate a carnivore diet. The low carbers know this so they whine about that no will fund them despite the fact that the meat industry revenue amounts to $125.60bn in 2023. Meat - United States | Statista Market Forecast
Oh yeah. I forgot. You can't trust any website with a .gov on it.

They also ignore the fact that there is only one medicare approved plan to reverse heart disease which advocates a whole food plant based diet. But then again, any information from the government can't be trusteed.
Provider Resource Center

They also have to disregard that the number one hospital for heart disease has a decades long program to reverse heart disease which espouses a strict whole food plant based diet.
The Esselstyn Heart Disease Program | Cleveland Clinic

And what about your poor kidneys?
Eating Too Much Meat Animal protein generates high amounts of acid in the blood that can be harmful to the kidneys and cause acidosis – a condition in which kidneys cannot eliminate acid fast enough. Protein is needed for growth, upkeep and repair of all parts of the body but your diet should be well balanced with fruits and vegetables.
10 Common Habits That May Harm Your Kidneys | National Kidney Foundation.

And of course the low carbers attack the blue zone book but somehow can't come up with any examples of carnivore populations that have the same similar long term health positive outcomes. The best they can come up with are the Eskimos. But that too was another one their false premises.
"The Eskimo Myth": The Truth About Heart Health

Well said.
I've tried every type of diet in my youth, and yes, low carb diets worked for weight loss, but I always felt deprived. Low fat diets never worked for me because I was never satisfied so I overate. Muffin after muffin after muffin... Or endless pasta. The best way to eat for me has been 1/2 plate of vegetable, 1/4 carb, 1/4 protein/fat. I feel satisfied and have kept my same weight for decades. And yes, alcohol in moderation!

True. Of course, if all you are eating for lunch is broccoli and cauliflower, you can eat a LOT more of it without overdoing the calories than if you are eating many other things. You could make a big pot of vegetable soup with lots of cabbage in it, stewed tomatoes, beans, and eat a quart at every meal and still lose weight, even if you stirred in a cup of brown rice.

This you stated is misinformation. Foods known to cause inflammation of the vascular system (grains, sugars, carbs) eaten in a routine diet which is high in cholesterol and bad type fats is what is currently believed to increase chances of heart attacks and strokes. Unfortunately, I'm living proof of this.

Skip the opinions and read about Blue Zones:

Blue zone - Wikipedia.

Most people are totally clueless about what is healthy to eat and they just don’t care. When I sit in a doctor’s office and look around 90% of the people there are grossly overweight.

Blue zones have been debunked as cherry picked and disingenuous info.

Issue #63: Beware of Netflix propaganda (Blue Zones debunked) - Heart & Soil Supplements

I think genetics may have something to do with it. Anecdotal personal evidence: my father was fundamentally a meat eater, and only ate twice a day. When he saw me eat salad he asked me when I’m going to start eating food. Not “rabbit food.” He was 10 pounds within the same weight throughout his adult life. My mother was mostly vegetarian with tiny bits of meat occasionally. Her weight fluctuated maybe 20 pounds throughout her adult life.

When I was 28 years old I tried the Atkins’s diet (in those days daily ketosis was required, for me 4 carbs a day or less) after 3 months I almost died from being overly weak etc. The doctor said I had extremely low potassium. I did lose any amount of weight I wanted though. My father never had low potassium and he was always active. My mother was a ranked gymnast. I am neither. And a vegetarian diet leaves me very low in iron although I try to compensate for it.

My observation is that genetics may influence what kind of diet is best for you.

Every major group of health researchers and doctors recommend the Mediterranean Diet. This proven diet has very little red meat in it, and complex carbs are hugely beneficial to us. If you think humans evolved to eat a lot of animal flesh, here's a question for you: Why did we evolve to have flat teeth (except for two tiny canines) primarily for grinding nuts, grains, fruit and seafood?

As the saying goes, don't make perfect the enemy of the good. On occasion I eat meat but it is not a large percentage of my caloric intake. Also the Mediterranean diet which includes fish has very positive outcomes relative to the standard American diet otherwise known as SAD.

But to advocate a diet of almost all animal protein is 100% pure quackery. It has not been or ever will be validated using established diet protocols. Or else they would publish them instead of making lame excuses.

I believe an elimination diet of any sort is bad for you. I know many, many vegetarians who became seriously ill, got cancer, or died in their sixties. As I understand it, you must eat a wide variety of fruits, vegetables, legumes, and grains each day to supply your body with the correct amount of nutrients. Most vegetarians do not do this. Man can not survive by eating broccoli, bananas, granola bars, and vegetable pizza. Then downing it with a tall glass of wine or coffee.

You can easily spot a vegetarian who is doing harm to themselves. They are frail/underweight and their faces are void of color. Avoiding meat does not mean you are eating healthy.

Yes, but that does not sell books and all the other diet businesses making a huge living out of unhappy people.