EP-3 Draft for Peer Review

John Sievenpiper L.—— An Expert of Carbohydrate Diets

A normal night I logged in Zoom as usual, however, started an extraordinary communication not as usual.

The host was John Sievenpiper, who is the author of a fabulous article “Low-carbohydrate diets and cardiometabolic health: the importance of carbohydrate quality over quantity” and is Associate Professor at University of Toronto. He has been eager to contribute his work to the nutritional field so that he has earned PhD. and MSc. in Nutritional Science at UT and also a member of Canadian Diabetes Association, American Society of Nutrition, Canadian Association of Medical Biochemists, and Diabetes and Nutrition Study Group of the European Association for the Study of Diabetes. His special enriching experience intensified my interests to meeting him and obtaining more knowledge.

Dr. Sievenpiper shifted his research since he realized the carbohydrate intaking have influence on cardiometabolic complications, including diabetes and cardiovascular disease. The conventional model of “energy balance” encourage public focus on dietary fat and calorie restriction, public has informed that eating less and moving more is the correct method to loss weight. However, “rates of obesity remain intractably high despite intensive focus on reducing calorie intake (eat less) and increasing calorie expenditure (move more), with major implications to well-being, life-expectancy, and health care costs” (Ludwig, Ebbeling 1). Recently. The new terminology “ketogenic diet” is prevalent among diet people and is supported by the mass trends and social media in the modern environment. The recent research provides mechanistic evidence in support of the carbohydrate-insulin model (CIM). “According to the carbohydrate-insulin model (CIM) of obesity, recent increases in the consumption of processed, high–glycemic-load carbohydrates produce hormonal changes that promote calorie deposition in adipose tissue, exacerbate hunger, and lower energy expenditure” (Ludwig, Ebbeling 1). However, “The current CIM model has not proved low-carbohydrates is beneficial to losing weight.” Dr. Sievenpiper said. Before his research, he investigated all the CIM documents and articles to study the advantages of CIM model. “CIM model just explained the consequences of highly intaking carbohydrates, this would cause endocrine deregulation, induce energy is stored more and lead to more and more food intake and decreasing energy expenditure.” Dr. Sievenpiper explained with more understandable language.

Nonetheless, carbohydrate is an essential nutrition source, and provide the major source of energy in the diet. “Carbohydrates are macronutrients and essential for body functioning. Actually, our body need large amount of them.” Dr. Sievenpiper pointed out the indispensable intake of carbohydrates. Carbohydrate contains carbon, hydrogen and oxygen from chemical perspective, and in our body, the most important and necessary macronutrients are carbohydrates, protein, and fats. “Carbohydrates provide fuel for the central nervous system and energy for working muscles. They also prevent protein from being used as an energy source and enable fat metabolism, according to Iowa State University… "carbohydrates are important for brain function," Smathers said. They are an influence on "mood, memory, etc., as well as a quick energy source." In fact, the RDA of carbohydrates is based on the amount of carbs the brain needs to function” (Szalay. 1). This is also a reason why Dr. Sievenpiper changed his consideration of quality instead of quantity. He believed the high-quality carbohydrate such as whole grains, pulses, or fruit which are low in glycemic index and load and high in fiber, would decrease cardiometabolic risk intermediately and are associated with weight less. In this way, the incidence of diabetes, cardiovascular disease, and cardiovascular mortality would decrease. However, he still mentioned some bad quality carbohydrates for example sugars, is harmful to our health, but is helpful to relieve stress. “Throughout the report it is apparent that carbohydrate consumption is relevant for individuals experiencing symptoms of emotional distress, particularly symptoms indicative of depression, and that the individuals with depressive symptoms show a preference for sweet simple carbohydrates” (Christensen, 1). The contradiction between calories intake and emotion regulator also was a consideration as well while Dr. Sievenpiper did the research. But finally, he decided to pay more attention to the quality of carbohydrates.

Nutritionists measure the quality of carbohydrates using carb’s glycemic index. Bad carbohydrates like pastries, sodas, and highly processed foods, white rice rise blood sugar rapidly and highly. Compared to this fact, good carbohydrates like vegetable, beans and whole grains raise the blood sugar gently and lower. This exploration stands a major support frame towards Dr. Sievenpiper’s research. Dr. Sievenpiper recommended people could try to convert the dietary structure. We could though the nutrients and the food form (nutrient-matrix interactions) gain various nutrition. In the daily life, we should take a consideration of food and nutrition interactions, especially on the diet. The last thing Dr. Sievenpiper emphasized several times was be sure to know the importance of being health rather than the rise and fall on the weighting machine.

Works Cited

David S. Ludwig, MD, PhD, and Cara B. Ebbeling, PhD. “The Carbohydrate-Insulin Model of Obesity Beyond ‘Calories In, Calories Out’.” JAMA Intern Med, 178 (8): 1098-1103, 2018. doi: 10.1001/jamainternmed.2018.2933. 2018. 07. 02.

Larry Christensen, Ph.D. “The effect of carbohydrates on affect.” Nutrition, vol.13, issue 6, June 1997, pp 503-514. doi: 10.1016/S0899-9007(97)00003-8. 1997.01.24.

Szalay, Jessie. “What Are Carbohydrates?” Live Science, 15 July 2017, www.livescience.com/51976-carbohydrates.html.