Do I Really Need To Wean My Baby Off the Bottle?

Hi, Prof. Oster! Do I really need to wean my 16-month-old off her bottle? She does not suck her thumb, and we do not breastfeed. She loves a bottle before nap, bed, and if ever having a tough time. Can we stop “when she’s ready” or should we really pull the plug?
—Annie

There are a couple of concerns about extended bottle use.

One is that it may be associated with children’s increased weight. The evidence for this is, in my view, very poor. We have observational studies like this one that show an association between extended bottle use and child weight, but where the extended bottle use is also associated with many demographics and with caregiver weight. It’s hard to eliminate the bias there.

A somewhat related concern is that extended bottle use will lead to nutritional deficiencies, if kids get too much milk and not enough non-milk foods (or too much juice or soda, if that is what you are putting in a bottle).

Finally, use of a bottle at bedtime for a child with teeth can lead to cavities. The milk sits on the teeth all night, and that can cause decay.

You will sometimes hear about links between bottle use and speech development, but that evidence is mixed at best.

If you can avoid these issues — in particular, if you are brushing your child’s teeth after the bottle (or at least rinsing their mouth) and they’re getting enough other food, there really isn’t any reason to pooh-pooh continued bottle use.