Knowing what human beings eat helps to. We are "starch adapted frugivores"(herbivore), not omnivores. We are designed to eat sugar and starch as 85-90% of our diet.
Carbs(sugar&starches) do not promote weight gain in overfeeding trails(I'm not allowed to post links):
1. The proccess in which glucose is converted to fat(de novo lipogenesis) has a 30% energy cost.
2. The reason people think they gain weight rapidly on carbs is because you can store up to 2 kilograms of glucose(from the carbs) in your liver, then you will have more weight from the glucose in your blood, then you can have up to several pounds of glycogen(glucose) stored in your muscle mass. Every 1g of carbs, retains 3g of water weight. Sodium retains tremendous amounts of water weight.
It is impossible to be trim or lean on the American diet without having an eating disorder.
A high-carb low fat vegan diet is not dangerous for type 1 & 2 diabetics, as you will see in the research of every doctor below(the exact opposite is true). Fat paralyses insulin, and blocks its receptors, and prevents glucose(blood sugar) from entering your cells to be metabolized into energy(anedosine-triphosphate). Sugar makes insulin work better.
I have used every diet in the world that involves eating food, and some that don't. I'm a sadist; I love to watch things suffer, and yet I'm still vegan. There's a good reason for it.
Unlike any carnivore, or omnivore:
We have a sacculated colon.
We have digestive enzymes in our saliva
Our stomach acid is pH 4-5(as with all herbivores), carnivores and omnivores have below pH 1 stomach acid.
You can look at everything about us and compare it to any omnivore you wan't, it is blatantly obvious.
I reference the following individuals back what I'm saying:
Dr. John Mcdougall
Dr. Denis P. Burkitt
Dr. Caldwell Esselstyn
Dr. T. Collin Campbell
Dr. Walter Kempner
Dr. Michael Kaplan
Dr. Neal Barnard
Dr. Michael Greger
We are not meant to count calories, it would make sense to do such an unnatural thing "if": having an abundance of food was unnatural, but that's not the case, the ancient peoples around the world had an overabundance of plant foods for thousands of years at a time(that's why the started building sh**) and they never had obesity epidemics. The only people that ate animal foods before 1700 A.D. were: wealthy, fat, and sick.
When it comes to looking at the other side of this:
If you look into the "Masai", who eat mostly beef and dairy: They look fit, but their average lifespan is about 50yrs, and autopsies from 300 specimens have revealed extensive atherosclerosis(risk of heart attack and stroke), capitations arteries(high risk of aneurysms), and osteoporosis(risk of bone fracture).
If you look into the Inuit Eskimos you will find even worse results.
I encourage anyone to see the contrast and look at both sides of this. Here are some opposing(low-carb, ketogenic) doctors:
Dr. Robert Atkins
Dr. Jeff Volek
Dr. William D. Davis
Professor Tim Nokes (known for his research in hyponatremia[water overdose])