From movie stars to athletes to students to peers, we are always comparing our bodies with one another. We are constantly asking ourselves the questions, “Why can I never gain any muscle?” “Why are my hips so big?” “Why does he/she look better then me?” and ultimately, this comes down to the major question “Why are we shaped differently?”
In the article, “Why are we shaped differently, and why does it matter?” the study focuses on “why different individuals preferentially store fat in the upper vs. lower body subcutaneous fat or subcutaneous vs. visceral fat.” They claimed that this mechanism was not completely understood, so the authors, Santosa and Jensen, decided to dig a little deeper.
Distribution of body fat is a predictor for metabolic abnormalities in the obese humans.
Metabolic complications exist more frequently in individuals with the upper body/visceral fat distribution compared with having lower body fat distribution (more fat around the abdominal organs = not good.) In other words, it is more detrimental for a human to have fat around the visceral area, more known as the “beer belly.”
Fortunately, for the Regis Biomedical Master’s students, we just VERY recently were tested on this phenomenon in biochemistry.
Most of the study is summed up in this picture. They examined the fatty acid kinetics over a 24-hour period between a normal weight man (15% body fat) and a normal weight woman (30% body fat). To read this picture, the green arrows represent the regional fat meal storage (assuming a 75g/day ingestion of meal fat had taken place). The blue arrows represent the direct storage for the FFA, and the red arrows indicate the regional flow of FFA during lipolysis. It took me awhile to understand this picture because the reader has to keep in mind the extreme differences in body fat between the male and female. The proportion of male fat storage in the abdomen (upper body) is much greater than in the leg, while the proportion for the abdomen versus leg fat storage is much less for the woman (suggesting the increase of fat storage in the lower body.)
Progress is still being made for the developing body shapes in humans, but they found that the more common accumulation of body fat in specific areas is due to preferential fat uptake in specific regions. (Male preferential fat uptake is in the abdomen, while women preferential fat uptake is in the legs.) At the end of the article they suggested that the LPL-mediated fat store might play a role. Questions that I had that were left unanswered were “why do some fat cells store more fatty acids than others? Would it have been more beneficial to do a study with a normal weight woman with lower % body fat?” While, many questions still exist about body types, I would imagine many pharmaceutical companies are investigating this matter greatly for possible drugs that would affect these certain LPL receptors (to benefit both health problems and weight loss issues).
Santosa, S. and Jensen, M. "Why are we shaped differently, and why does it matter?" AJM-Endocrinology and Metabolism. 295. (2008): 531-535.
As you have stated, the distribution of body fat can be predictor for metabolic abnormalities humans if an individual has more fat around the abdominal organs ( I would assume this is bad because fat would clog up arteries so essential organs wont receive enough oxygen. And you’ve also stated that men tend to accumulate more body fat around the abdominal organs while women tend to accumulate more body fat on their legs. This information leads me to think that men would tend to have a higher incidence of metabolic abnormalities. I am wondering if in your research, you came across as a statistics that supported my assumption?
ReplyDeleteAfter reading this summary, I was left wondering how hormone differences in both genders could possibly lead to the differences in specific regional areas of storage of fatty acids (since it is well known hormones play a huge role in fat storage, I’m wondering if they can dictate where the accumulation of that fat occurs?). For example, it has been suggested that the increased estrogen levels in women is the cause of fat stores to accumulate in the lower body region, but has there been study’s or research to show how this occurs or why this occurs? The same question can be applied to men, how hormones could play a role in dictating buildup of abdominal fat?
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