Introduction
There is an obesity epidemic in the Western world. In this write up we will be discussing obesity, its causes and the role biochemistry can play to help provide solutions to this issue.
Obesity is a condition in which the body weight increases above the limits of a physical requirement due to excessive accumulation of fat and increased adipose tissue mass (Sikaris, 2004). Obesity cannot only be defined in terms of body weight, because short people are expected to be lighter than tall people, body weight needs to be standardised against height. This is best expressed in body mass index (BMI), which is calculated as weight (kg) divided by height (m2) (Sikaris, 2004).Thus, Let us look at biochemistry of some of the leading causes of weight gain and obesity
Biochemistry or biological chemistry is the study of chemical activities within and relating to living things. Biochemical activities give rise to life complexity through biochemical signalling and metabolism.
Leptin Resistance: Leptin a hormone synthesized and secreted by adipose tissues. Stimulates the hypothalamus, this part of the brain that tells us we are not hungry to reduce food intake and increase energy expenditure (Rosen and Spiegelman, 2006). In leptin resistance, the body does not respond to leptin hormone leading to fat gain (Sáinz et al, 2015).
Insulin resistance: Insulin is an important hormone that regulates body sugar and energy store. In insulin resistance, cells do not respond to insulin causing the energy to get stored in fat cells instead of being used (Esmaillzadeh A et al, 2007).The role of insulin is controversial but some studies propose high insulin levels have a role in obesity development (Templeman NM et al, 2017).
Genetics: Children of obese parents are likely to become obese than lean parents. Also the type of food one eats has an effect the type of genes expressed and those that are not. Genetics mechanisms affect one's vulnerability to gain weight. This is well demonstrated by studies on identical twins (Bouchard C, et al 1990).
Sugar: Added sugar may be the single worst aspect of the modern diet. The sugar alters the hormones and biochemistry of the body when consumed in excess, and contributes to weight gain. People get glucose from different types of food, including starches, but majority comes from added sugar. Surplus fructose intake may cause insulin resistance and elevate insulin levels. For all these reasons, sugar contributes to increased energy storage and, ultimately, obesity. The high flux of fructose to the liver disturbs hepatic carbohydrate metabolism causing two main consequences perturbations in glucose metabolism, glucose uptake pathways and improved rate of de novo lipogenesis and triglyceride synthesis (Basciano, et al 2005).
Health complications of obesity
Health complications associated with obesity include type 2 diabetes, heart disease, high blood pressure, certain cancers (breast, colon, and endometrial), stroke, gallbladder disease, fatty liver disease, high cholesterol, sleep apnea and other breathing problems, arthritis and infertility (Haslam and James, 2005)
What can biochemistry do to provide a solution to this health problem?
The solution to the obesity epidemic may appear easy on the surface, eat less and exercise more, but in reality, change is difficult to achieve and research to address this issue is critical. Part of the efforts to tackle this problem is the National Institutes of Health (NIH) supported obesity-related research in genetic, environmental, clinical, epidemiology and molecular studies. This includes short, intermediate, and long-term goals, population and clinical based research.
These goals are organised into four themes:
- Research toward preventing and treating obesity through lifestyle modification: This is set to identify modifiable behavioural and environmental factors leading to the development of obesity in children and adults.
- Research toward preventing and treating obesity through pharmacologic, surgical approaches: Genetic and molecular studies may help with potential targets for new drugs.
- Research toward breaking the link between obesity and its associated health conditions: understanding the link between obesity and type 2diabetes, cancer, cardiovascular disease, cell metabolism and the mechanisms of body fat deposit in causing insulin resistance will help to know the mechanisms linking obesity to other health condition and can make it possible to break the link between them.
- Cross-cutting research topics, including health disparities, technology, fostering of multidisciplinary and interdisciplinary research teams, investigator training, translational research, and education/outreach efforts. (Spiegel and Alving, 2005).
Researchers in biochemistry are also working had to know how leptin, ghrelin, glucose, hormone, insulin amino acid, enzymes, vitamins and other chemicals intermingle to metabolize the chemical (food) to be used as energy, build muscle or store(Chabot, 2014).
Studies have revealed that understanding the biology of adipogenesis may lead to a solution to the obesity pandemic. Also knowing the biology of adipocytes is essential to understand the pathophysiology of obesity and type 2 diabetes (Rosen and Spiegelman, 2006). Researchers are sure that manipulation of adipocyte biology by improvement of leptin and adiponectin production will be a good strategy for fighting the obesity epidemic. As they stated the reactivation of brown adipose tissue (BAT) in adult’s humans is a good solution for a successful treatment for the obesity epidemic (Çakmur, 2017).
Conclusion
Obesity is yet to have a cure but can be prevented and treated. Weight loss can improve or prevent the problems liked to obesity. Increase exercise good diet can help in weight loss. Medication and weight loss surgery are options for treating obesity. There are several on-going types of research to understand the biochemistry of obesity that may possibly come up with a cure, proving a solution to the obesity pandemic.
References
- Basciano et al, (2005). Nutrition & Metabolism, 2(1), p.5. [Online] Available at: 10.1186/1743-7075-2-5 [Accessed 31th January 2019].
- Bouchard C, et al. (1990). The response to long-term overfeeding in identical twins. - PubMed - NCBI. [Online] Ncbi.nlm.nih.gov. Available at: https://www.ncbi.nlm.nih.gov/pubmed/2336074 [Accessed 30th January 2019].
- Çakmur, H. (2017). Obesity as a Growing Public Health Problem. Adiposity - Epidemiology and Treatment Modalities. [Online] Available at: 10.5772/65718 [Accessed 31th January 2019].
- Chabot, F. (2014). Interrelationships between ghrelin, insulin and glucose homeostasis: Physiological relevance. World Journal of Diabetes, 5(3), p.328. [Accessed 27th February 2019].
- Clearlyexplained.com. (2019). Biochemistry | ClearlyExplained.com. [online] Available at: http://clearlyexplained.com/biochemistry/index.html [Accessed 27th February 2019].
- Disorders, 13(10), pp.423-444 [Online] Available at: https://dx.doi.org/10.1089%2Fmet.2015.0095 [Accessed 31st January 2019].
- Esmaillzadeh A, et al, (2007). Dietary patterns, insulin resistance, and prevalence of the metabolic syndrome in women. - PubMed - NCBI. [Online] Ncbi.nlm.nih.gov. Available at: https://www.ncbi.nlm.nih.gov/pubmed/17344515 [Accessed 29th January 2019].
- Haslam, D. and James, W. (2005). Obesity. The Lancet, 366(9492), pp.1197-1209. [Online] Available at: https://doi.org/10.1016/S0140-6736(05)67483-1 [Accessed 31st January 2019].
- Manna, P. and Jain, S. (2015). Obesity, Oxidative Stress, Adipose Tissue Dysfunction, and the Associated Health Risks: Causes and Therapeutic Strategies. Metabolic Syndrome and Related
- Rosen, E. and Spiegelman, B. (2006). Adipocytes as regulators of energy balance and glucose homeostasis. Nature, 444(7121), pp.847-853. [Online] Available at: https://doi.org/10.1038/nature05483 [Accessed 31st January 2019].
- Sáinz N, et al (2015). Leptin resistance and diet-induced obesity: central and peripheral actions of leptin. - PubMed - NCBI. [Online] Ncbi.nlm.nih.gov. Available at: https://www.ncbi.nlm.nih.gov/pubmed/25497342 [Accessed 29th January 2019].
- Sikaris, K. (2004). The Clinical Biochemistry of Obesity. [Online] PubMed Central (PMC). Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1880830/# [Accessed 29th January 2019].
- Spiegel, A. and Alving, B. (2005). Executive summary of the Strategic Plan for National Institutes of Health Obesity Research. The American Journal of Clinical Nutrition, 82(1), pp.211S-214S. [Online] Available at: https://doi.org/10.1093/ajcn/82.1.221S [Accessed 20th February, 2019].
- Templeman NM, et al. (2019). A causal role for hyperinsulinemia in obesity. - PubMed - NCBI. [Online] Ncbi.nlm.nih.gov. Available at: https://www.ncbi.nlm.nih.gov/pubmed/28052999 [Accessed 29th January 2019].