It seems I’m fat because I’m the oldest of four daughters. Just another reason to hate my baby sister. I don’t really hate her, but it makes for a good read to say something so obnoxious. It is true. I am fatter than my youngest sister. In fact, I’m fatter than all of my sisters. I just thought it was because I was older and when they reached the age I am now they would achieve the same level of fatness. Now that I’ve read the new findings from a study at the University of Auckland, I have discovered that I will always be the fattest simply because I am the oldest.

These New Zealand scientists studied over 13,000 sisters for about twenty years. They collected medical data that concluded that the first born daughter is almost always bigger from birth. She will grow up to be a taller, heavier adult than her younger siblings. Simply because of birth order, it is almost thirty percent more probable that I will outweigh my younger sisters and forty percent more likely that I will be obese. I don’t know whether to be depressed, mad or at peace with my fatness fate.

The leader of this study considers that these differences could be caused by the changes that take place in the placenta between births. During the first pregnancy, the theory is that the mother’s blood vessels may be more constricted. This restricts the flow of nutrition that reaches the baby. The result of such nutritional deficiency could be that the baby matures into an adult that does not regulate glucose and fat efficiently. Another hypothesis is a bit simpler. It could just be that mom and dad fuss like crazy over that first baby, indulging and overfeeding the baby into a plump little future fat person. I like the “blame the parents” approach, myself. Then I don’t feel doomed to a lifetime of fatness due to an inefficient metabolism. If it’s my parents fault there is at least hope that I can simply relearn my early conditioning regarding my relationship with food.

Doctors have long considered that birth order has significant effects upon personality and intelligence. First children typically have higher IQs than their younger siblings. They also tend to be more extroverted and easier to get along with. Younger siblings, particularly the last-born, are usually more demanding, less intelligent and have a tendency to be more irresponsible.

To put this in perspective, out of the first twenty-three astronauts that launched into outer space, twenty-one of them were the first-born in their respective families. Perhaps this trend of overachievement develops out of the tendency of first-born children to learn responsibility early. My childhood memories are filled with images of my mother being pregnant yet again. I remember when I found out she was once again pregnant with little sister number three, my youngest sister. I was so very mad. I felt that life was just so unfair. I was determined to hate that upcoming intruder for the rest of her life. My mother did not have easy pregnancies. I would usually help with cooking and cleaning because she was usually on bedrest. And the thought of one more little one that I had to keep out of my things and help pick up after and keep an eye on was maddening.

The best news of all is not discovering why I am fat. The best news is that all these years later, after determining a course of action to hate my younger sisters for the pains in the rear that they were, I still love them to pieces. We did what most sisters did. We fought like cats and dogs while we had to share turf in the family home. Then, one by one, as we moved out and got our own places, we missed each other like crazy. We eventually forgot about all the things that annoyed us about one another and realized we were the best friends we have ever had, one of us will just always be the fatter friend.