Supposedly it is just too difficult to eat excessive calories when eating only meat and fat.
OK, a thought experiment.
Let's say that Venus is 100 pounds overweight. That translates to 350, 000 stored calories.
Let's say she ate only 100 excess fat calories every day...about two teaspoons of pure fat.
No one can tell me that it is too difficult, too painful, impossible to eat two teaspoons more fat than you need every day.
There were plenty enough calories available in ice age Europe for any one to have 100 extra calories per day on average. They were hunting critters like mammoths:
These animals had 20-30% body fat, and weighed on average 6-8 tons, i.e. 1200 to 1600 pounds. One animal would provide at least 240 pounds or more of adipose tissue: 840, 000 calories of pure fat. Twenty people (the estimated typical size of a paleo tribe) would have had 420, 000 calories each just from the fat of one animal, and upper Paleolithic people were killing these animals en mass.
She starts at age 20. How long will it take her to store up that excess 100 pounds?
One hundred excess calories per day for 3500 days, about 10 years, will result in 100 pounds of excess adipose weight.
She is obese by age of 30. From a measly two teaspoons daily of excess animal fat.
People don't grow obese in a year or two. It takes time.
As Stephan pointed out recently, the reward value of food plays a dominant role in the genesis of obesity. Stephan wrote:
"Experiments in rats and humans have outlined some of the qualities of food that are inherently rewarding:Upper paleolithic diets of Europe had fat, meatiness, and caloric density; all inherently rewarding. Its easy to eat those extra two teaspoons of fat, your brain rewards you for it and you certainly do not get a stomach ache from it.
We are generally born liking the qualities listed above. In addition, aromas and flavors that are associated with these qualities can become rewarding over time."
- Meatiness (glutamate)
- The absence of bitterness
- Certain textures (e.g., soft or liquid calories, crunchy foods)
- Certain aromas (e.g., esters found in many fruits)
- Calorie density ("heavy" food)
Compare, in your own experience, the pleasure you get from eating fat, to the pleasure you get from eating boiled potatoes, sweet potatoes, or rice served without any fat. Which do you enjoy more, one 4-ounce boiled potato (about 100 kcal), or two tablespoons of cream (also about 100 kcal).
Its obvious which has the higher caloric density. Your brain gets more reward from the cream than the potato. Which reminds me, I've never met a person who binges on boiled potatoes.
Moreover, when we eat extra carbohydrate, it increases metabolic rate by about 10% of the calories consumed, and converting carbohydrate to fat consumes at least 10% of the calories in the carbohydrate. But eating extra fat has no thermogenic effect, and since it is already fat, ready to store, essentially none is lost in the process of storage.
This means most people find it a little more difficult to consume excess energy in the form of whole food starch (e.g. potatoes) compared to consuming excess energy in the form of fat.
If carbohydrates make people fat, then why does Japan have an obesity rate of only 3.2%, in comparison to the Grecian 22%? Seven times more obesity in Greece, than in Japan.
Grecian diet: About 40% energy from fat, 45% from carbohydrate
Japanese diet: About 60% energy from carbohydrate (mostly white rice), 25% from fat
A beautiful theory slain by ugly facts? Make your own conclusions.
By the way, you don't need "high" insulin to store fat. You just need 1) normal insulin (not type 1 diabetic), 2) acylation stimulating protein, a potent regulator of fat synthesis, and 3) an excess of dietary fat.
I can easily imagine Venus eating just a little too much meat and fat often enough to average an extra 100 calories daily, for 10 or more years, gradually growing obese. Her intake just exceeds her output by a small amount. The same way that people grow obese today...over a long period of time, with no obvious overeating.
I simply do not find compelling any attempt to explain Venus by force-feeding rituals, potato or honey binges, or similar scenarios. People do not get obese like this in a month, and ice age Europe most likely did not supply any carbohydrate-rich foods in quantities necessary to make them responsible for this level of obesity.