2000 babies were studied (note, I have not read the actual study yet...) The way it is being reported is almost more interesting.
Basically every story said that infants under 6 months with more rapid weight gain had a 40% higher chance of being overweight at age 3. Many infants with higher weight initially may be genetically predisposed to being larger, but can still be healthy. I did not get a sense for the degree of weight difference. Remember, in a 3 year old, as little weight difference as 5 pounds can span the range from "normal" to "obese."
I will scan for a more scientific rebuttal and post it when I find it. Of note, breastfeeding, which the media claims will protect our children from obesity, (more guilt and fear for moms who had trouble with that) was not found to make a difference in this study. I did not see any explanation for that, other than one article, despite saying there was no difference making the claim that it was much easier to overfeed a bottle fed baby than a breast-fed baby. (Pseudi-science or no science conclusion. If it is "much easier" to overfeed a bottle fed baby, why did they find no difference?) There are too many questions, and not enough hard data, back-up, long-term follow up to warrant the media frenzy.
Meanwhile the hysteria continues. I think of my parent classes that I teach, and the moms of infants, one of whom compared feeding her healthy nine-month-old to "living on knife-edge between anorexia and obesity." Does it have to be so hard?
My daughter was 9 lbs 11 ounces at birth (I had a normal pregnancy, gaining about 30 pounds.) She was off the charts, and stayed that way until about age 2. Only then did she start to come down onto the curve, and now at 3 1/2 is just under 90% which is still considered "overweight." She is "slimming down" and I am not doing anything other than feeding her in a trusting way, with mostly healthy food most of the time. She gets to eat ice-cream, fruit juice, and sometimes eats alot, sometimes a little. Most large infants will slim down if we don't intervene and restrict their intake. HOW we feed is critical. The Division of Responsibility will allow most children to grow at a steady, predictable rate, and there will naturally be some children larger than others.
This news is being reported so ambiguously. I fear that parents will read this and try to limit their infants' intake and will not trust to feed a larger infant on demand. The poor baby! To deprive a baby of food (what other message can parents take away when exorted to "maintain a healthy weight for their infants") is cruel. Infants will auto-regulate. Some infants will be big, and grow more quickly. If there is a true accelaration and crossing into higher percentiles, then there should be a discussion, but the message that a baby can be at the 100% or more and still be healthy is not in these stories. (It is possible that some parents overfeed. Why not have the story be about learning to listen to baby's cues for hunger and satiety? If a baby turns his head away, or pushes the bottle away, then they are indicating they are full. I did not see any mention in this study of HOW the parents are feeding...)
I recently saw my daughter's Great-grandmother's baby pictures. Born 90 years ago at 10 lbs 4 ounces, she is now on no medications and is a ping-pong and bridge champion. She chuckles about her "baby fat" in her 3 year old picture. Please let's not lose sight of common sense and give in to fear mongering. We do need to address how to properly feed children, but small studies with questionable conclusions screamed in the headlines to already anxious parents is not the answer.
As my mentor taught me when I was worried about my big baby, "Bigger kids are harder to trust, but they are trustworthy." Let's not make matters worse by intervening inappropriately and causing the outcomes we are trying to avoid.