Obesity – It’s not just for the Wealthy Anymore
I don’t need any statistics to convince you that obesity is a problem in America. On evening news shows there are frequent segments concerned with the recent rise of obesity, often focusing on the growing rate of childhood obesity. In 2003, the surgeon general named obesity “the fastest-growing cause of disease and death in America,” and it hasn’t slowed down any since then. The article we read in class called it an urgent health issue and hoped that some of the research it presented and hypotheses it put forward might lead to further research leading to more effective and practical forms of obesity treatment.
Insulin and Leptin – the Dynamic Duo
After eating a large meal, there are a number of processes that should begin to properly utilize and store the food that was just consumed. Many of these processes are directed by the action of leptin and insulin acting cooperatively. Insulin signals cells to take up glucose from the bloodstream and either use it as energy or store it as glycogen. Leptin, on the other hand, plays a crucial role in telling the brain that enough food has been consumed and acts as an indicator of energy balance. When insulin control fails the result is diabetes, which prevent effective insulin signaling and allows blood-glucose levels to increase to toxic levels. A failure in leptin signaling leads to uncontrolled appetite and usually obesity.
Insulin and leptin act in part by activating neurons in the hypothalamus that express proopiomelanocortin, which release a neuropeptide that tells the brain to reduce food intake and increase energy expenditure. Alternatively, they prevent the activation of another type of neuron in the hypothalamus that signals the body to promote food intake and decrease energy expenditure.
Too Much of a Good Thing
Why are these hormones failing in the modern diet? In the modern world the cheapest food, which often also tastes pretty good because of high-fructose corn syrup, is highly processed. This means it is packed full of calories, fat and plenty of other nonsense, literally (read the ingredients on a pack of candy or a bag of chips and tell me how many food products you recognize from your kitchen). The types and the amounts of the foods we eat are stupefying our bodies ability to sense satiation and undergo properly metabolism. Studies described in our article have shown that high fat diets can lead to insulin-resistance, while consistently high levels of leptin, likely from overeating three times a day and filling in the meantime with snacks, leads to leptin-resistance. When the body becomes resistant to these hormones it no longer realizes when enough food has been eaten and has a hard time properly utilizing normal quantities of food, much less the extra portions added on from the lacking brain-to-body signals. Fructose, a sugar that makes up about half of high-fructose corn syrup, has also been blamed for leptin resistance.
The Frosting on the Cake
Maybe in this case I should say the low-fat ranch dressing on the baby-carrots. Although obesity is a huge problem it is also largely preventable. Reducing food intake and exercise are old standbys to combat obesity. The article mentions that keeping a low calorie diet can increase levels of leptin in the blood thus helping the body to be satiated after less food. This means that if a diet is stuck with long enough it should become easier and easier as time passes. However, diet and exercise are not easy in a fast paced world like the one we currently find ourselves in. This is where further research into the action of leptin and insulin may come to the rescue. By better understanding how these hormones affect appetite and metabolism, new treatments may become available to help get the jump on obesity and create a healthier modern world.
Too Much of a Good Thing
