Probably the best academic treatment of why modern foods play a role in diseases of civilization.
Biologically appropriate childcare without being child-centered in the Aka
The Aka pygmies are nomadic horticulturalists that trade with nearby farmers for staple carbohydrates. I've written about the pygmy diet before, but variations exist among the various pygmy tribes in terms of culture. The Aka are considered "the best fathers in the world," at least among studied tribal peoples. While fathers play an important role in every tribal culture, one that liberal cultural anthropologists have tried to play down with disputed anecdotes about some cultures that may not have ideas about paternity, the Aka are still unusual in the importance of fathers. Their culture is distinguished by close bonds between couples, who net-hunt together to provide food for the family. Fathers participate in childcare and hold their children for many hours. The article linked to above is false in that there are still non-interchangeable gender roles, but genders are much less differentiated than in most tribal cultures.
In the book Intimate Fathers they describe how, like the Yequana, the Aka parents are physically indulgent, but not emotionally smothering. Many modern parents are excessively child-focused and protective, yet neglect the basic biological needs of their babies for physical closeness with their biological parents (and other relatives) and breastmilk.
Aka infancy is indulgent: infants are held almost constantly, they have skin-to-skin contact most of the day as Aka seldom wear shirts or blouses, and they are nursed on demand and attended to immediately if they fuss or cry. Aka parents interact with and stimulate their infants throughout the day. They talk to, play with, show affection to, and transit subsistence skills to their infants during the day. I was rather surprised to find parents teaching their eight-to-twelve-month-old infants how to use small pointed digging sticks, throw small spears, use miniature axes with sharp metal blades, and carry small baskets. Most of this direct teaching takes place while resting on the net hunt.
While Aka are very indulgent and intimate with their infants, they are not a child-focused society. Some have suggested that many American parents are child-focused, in that parents will give undivided attention to the child (quality time) and dramatically change their behavior or activities to attend to the desires of the children. American parents allow their children to interrupt their conversations with other adults; they ask their children what they want to eat and try to accommodate other desires of the children. Aka society is adult-centered in that parents seldom stop their activities to pay undivided attention to their children. If an infant fusses or urinates on a parent who is talking to others or playing the drums, the parent continues his activity while gently rocking the infant or wiping the urine off with a nearby leaf. There are times when the infant's desires are not considered and the infant is actually placed in danger by the parents. For instance, on the net hunt, if a woman chases a game animal into the net, she will place the infant on the ground to run after the game and kill it. The infant is left there crying until the mother or someone else comes back.*
*women don't participate in the most dangerous hunts, like the elephant hunt