YBurnMeat ?
Because human is Herbivore

Brain Size, Gestation & Number of Babies
  

Dog Litter Pig Litter


Gestation # ofLifespan



Months BabiesYears

Herbivore
Cow 9 115-20

Herbivore Horse 11 125-30

Herbivore Donkey 11-14 1 27-40

Herbivore Orangutan
9 130-60
Has Big Brain
Herbivore Gorilla 9 135-40
Has Big Brain
HerbivoreLlama11120

HerbivoreZebra11-13120-40

HerbivoreElephant22165
Has Big Brain
Herbi-Omni Chimp 8 115-30

Omnivore Baboon
6
1-2
20-30

Omnivore Pig 4 1015-20

Omnivore Dog 2 5-810-13

Carnivore Lion 4 2-68-16

CarnivoreCat22-613-17

CarnivoreHyena3-41-312

Carnivore Dolphin 12 155-60
Has Big Brain

Conclusion:  Among land mammals over 30 LBs, most herbivores have longer gestation (>8 months) and give birth to one baby at a time. 
Whereas ALL omnivores have shorter gestation (<6 months) and give birth to multiple babies at once. 

Given the complexity of the brain, a longer gestation period of herbivores (9 months) provides more time for brain development of a single baby in the womb

Evidence-ProofAccording to research, the rate of mental retardation is generally considered higher among twins and premature births, primarily due to the increased risk of lower birth weight and shorter gestational age, which can impact neurodevelopment.

Please also see:
Fastest Brain Growth (human baby's brain) on lowest % Protein (Human Breast Milk)

Ray Arjo  FB   5/2023

Based on pictures among apes, the more meat in the diet, the smaller the brain & body.

Among Apes, More Meat in Diet=Smaller Brain