Written by Mita Majumdar, M.Sc. | 
Medically Reviewed by dr. reeja tharu, M.Phil.,Ph.D on Jul 06, 2018

Carbs, Obesity and Type-2 Diabetes

"If we could eliminate sugary beverages, potatoes, white bread, pasta, white rice and sugary snacks, we would wipe out almost all the problems we have with weight and diabetes and other metabolic diseases," according to Dr. Walter Willett, chairman of the Department of Nutrition at the Harvard School of Public Health and a professor of medicine at Harvard Medical School.

This has been corroborated by an interesting study published in the Journal of American Medical Association. This study by Schulze and colleagues provides further evidence that excess calories from sugar-sweetened soft drinks lead to obesity among adults and are also the cause of type-2 diabetes. The researchers, however, found that consuming fruit juices was not associated with an increased risk of type-2 diabetes. They suggested this could because of lower GI of fruit juices or possibly the fiber and phytochemicals present in them that could be beneficial.

Numerous researches demonstrate that dietary sucrose (glucose) does not increase blood glucose levels in the body any more than starch with the same caloric value. And fructose occurring naturally in fruits and vegetables are known to produce lower postprandial glucose response. So, you need not restrict dietary fructose or sucrose in your diet even if you are a diabetic.

However, use of added fructose as a sweetening agent is not recommended since studies have proved that high amounts of fructose may adversely affect plasma lipids. One such study published in the Journal of the American Medical Association assessed the association between consumption of added sugars and blood lipid levels in American adults. The researchers found that among consumers who took greater than or equal to 10 percent added sugars the odds of low HDL-C levels were 50-300 percent greater compared with the group who consumed less than 5 percent added sugars. They concluded that ‘there was a statistically significant correlation between dietary added sugars and blood lipid levels among US adults’.

Apart from low HDL cholesterol, fructose also leads to small dense LDL, atherogenic dyslipidemia and insulin resistance. Moreover, researches have shown that consumption of added fructose promotes abdominal obesity which increases risk for type-2 diabetes and cardiovascular disease.

The American Heart Association recommends no more than 100 calories (6 tsp) of added sugar per day for women and 150 calories (9 tsp) of added sugar for men. It further recommends limiting sugar-sweetened beverages to 450 calories or less per week for a 2000-calories-diet. This recommendation is not only to prevent obesity and heart related disease but to avoid the risk for type-2 diabetes as well.


  1. Bray GA, Nielsen SJ, Popkin BM. Consumption of high-fructose corn syrup in beverages may play a role in the epidemic of obesity. Am J Clin Nutr. 2004 Apr;79(4):537-43.
  2. Ferder, L. et al. The Role of High-Fructose Corn Syrup in Metabolic Syndrome and Hypertension. Current Hypertension Reports Volume 12, Number 2, 105-112, DOI: 10.1007/s11906-010-0097-3
  3. Nagai et al. The Role of Peroxisome Proliferator-Activated Receptor Coactivator-1 in the Pathogenesis of Fructose-Induced Insulin Resistance. Cell Metabolism, 2009; 9 (3): 252-264
  4. Welsh J.A., et al. Caloric Sweetener Consumption and Dyslipidemia Among US Adults. JAMA. 2010;303(15):1490-1497. doi: 10.1001/jama.2010.449
  5. Sugar-Sweetened Beverages and Risk of Metabolic Syndrome and Type 2 Diabetes - (http://care.diabetesjournals.org/content/33/11/2477.full)
  6. 2nd study - Schulze MB,Manson JE, Ludwig DS, et al. Sugar-sweetened beverages, weight gain, and incidence of type 2 diabetes in young and middle-aged women. JAMA. 2004;292:927-934.

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