Obesity in Our Lives

Part A: Over the past twenty years, the obesity rate of Americans has dramatically increased. There have been studies that show a direct link between childhood obesity and drinking large amounts of sugar-sweetened beverages. HFCS stands for High-fructose Corn syrup and table sugar, also known as sucrose, are both made up of two sugar molecules, glucose and fructose. These sugar molecules are found in relatively equal amounts and are considered chemically equivalent according to scientists and doctors. Glucose is not considered a dangerous sugar to consume and was even referenced in the article “The Truth About Sugar” as “ the body’s preferred fuel, the type that smoothly runs the billions of cells in our body”. However, fructose is the opposite, it was referenced as a chronic poison that will eventually kill you. Dr. Robert Lustig is quick to state that only the added sugars are bad for you and that natural fructose is not something we should look out for.

Unfortunately, these added sugars are found in processed foods and sugary beverages which is what the majority of American eat on a daily basis. Dr. Lustig states in the article that the average American eats 200 to 300 extra calories per day. The amount of fructose consumed is the cause of many life-threatening diseases including metabolic syndrome, the constellation of disorders, including type 2 diabetes, cardiovascular disease, and fatty liver disease. The majority of the cells in our body use glucose to break down and use for energy. The organ that metabolizes the fructose we eat is the liver. This is harmful to the human body because our livers cannot break it down fast enough to make it into energy so the high concentration of fructose sitting in our liver becomes citrate. Citrate is the raw material of triglyceride which is a fat molecule. When there is too much triglyceride in the blood it can cause cardiovascular disease and Type 2 diabetes. Eating too much fructose can lead to an inflamed liver and high blood pressure.

Part B: Many experts do not believe Dr. Lustig “toxic-sugar” theory because of the fact that Dr. Lustig did not perform his own experiments to reach the conclusion he did. Dr. Lustig is not a fructose researcher which adds to the doubt many experts have in his theory and in the text, his theory is referred to as a hypothesis because it is not proven. The majority of the papers he has written on the effects of fructose were mainly focused on obese children which could lead to many confounding variables due to not having enough diversity. Dr. Lustig has written around 90 papers and only six that talk about fructose. Of the six that talk about fructose, only two were written before his theory went viral. The research that Dr. Lustig looked at were tests done on animals, which is not an accurate reflection of the effects fructose has on the human body due to the difference in how humans process carbohydrates compared to how animals. In addition to the difference in how humans and animals process carbohydrates the amount of fructose given to these animals were much larger then what most humans consume in their lives.

David Katz is one expert who does not agree with Dr. Lustig theory, he believes that Lustig’s theory is an extreme point of view for the effects of fructose in our body and that the theory only got attention because of its extreme point of view. The article also references a study done by George Bray, M.D. that states how the increase in obesity due to the intake of sugar “loosely attributes” to the way our body metabolizes fructose. Another example in the article was the Women’s Health Study which concluded that people who consume the minimum and maximum amount of HFCS have the same amount of risk of obtaining diabetes. However, Dr. Lustig’s theory is supported by other experts but is still hard to find solid evidence for due to conflicting data from various tests. The Nurse Health Study is one study that supports Dr. Lustig’s theory, this study found that if you were to drink a small glass of fruit juice a day your risk of type 2 diabetes would dramatically increase and that people who drink one soda a day have a high risk of getting heart disease.

More tests that were done in labs where they had little confounding variables concluded that when we consume high amounts of fructose the number of triglycerides in our blood increases and the more fat deposits in our muscles and liver but our overall body weight and blood pressure does not increase any more than if we were to consume a different type of carbohydrate. Americans have nearly doubled the amount of money we spend on processed foods that are high in fructose then what we spent 20 years ago, as this spending on fructose has gone up so has the obesity rate of Americans. The final study talked about in the article was conducted at UC Davis by Kimber Stanhope, Ph.D., and Peter Havel, D.V.M, Ph.D., which concluded that people who consume high amounts of fructose have higher amounts of triglycerides in their blood and lower amounts of insulin which overall increases their risk of diabetes greatly. The subjects also had high amounts of visceral fat which are heavily associated with metabolic syndrome which was also found in the animal’s studies Dr. Lutsig looked at to write his paper.

Part C: The study “Fructose consumption: Recent results and their potential implications” written by Kimber L. Stanhope and Peter J. Havel had mostly valid experimental design based upon the scientific method however it could be improved if they were to replicate this experimnet and get the same results over again. The authors of this studies are also the ones who conducted the study which is important because they understand everything about the experiment because they performed it themselves. The researchers used human subjects and the sample sizes of both experimental groups are unknown. There was no control group or placebo used in this experiment, only two experimental groups, one having the subjects consume fructose beverages and the other consuming glucose beverages.

The duration of this study was 10 weeks which is relatively a short amount of time. This experiment was not controlled and had lots of possible confounding variables. It is not likely that the subjects or researches would have biases in this experiment which could cause confounding results. This is known because there would be no reasoning for bias if everyone in the study is getting experimented on and all subjects are virtually equal. This was not a blind or double-blind study because both the researchers and subjects knew what they were consuming. The subjects were older overweight adults who were consuming beverages high in fructose. This makes a more general conclusion about the effect of these sugars in your body and their long-term effect.