jay wrote:

Per Wiki, human milk is 62% fat, 32% carbs and 5% protein by calories.
Another source says that of the fat, 41% is saturated.
Would this be considered a high-fat diet?
Does T2D start with breast milk???

It does explain why some diet plans discourage drinking milk after
weaning. Mammals in general don't eat dairy after weaning. Eating
dairy by humans is recent and lactose tolerance has not yet evolved into
our entire population.

Opinions about what' high/low fat/carb vary. I would call that a high
carb diet but not a high fat diet. My bias.