Impact of Carbohydrate Intake on Obesity in Japanese Patients with Type 2 Diabetes—An Analysis of the JDCP Registry
Authors: MATSUNAGA SATOSHI , SONE HIROHITO , TSUDA KINSUKE , OSHIDA YOSHIHARU , SASAKI SATOSHI , SATOH JO , HAYASHINO YASUAKI , NISHIMURA RIMEI , TAJIMA NAOKO 
Published: June 2018

While the clinical relevance of a low carbohydrate diet for obese patients with diabetes is still a matter of debate, the optimal amount of carbohydrates has not yet been elucidated. Therefore, we investigated the association between obesity and the carbohydrate intake while considering the physical activity (PA) levels in patients with type 2 diabetes. Japanese patients with type 2 diabetes in a nation-wide registry who completed a lifestyle survey, but were not administered insulin therapy (N=1111, mean age 61.7 y, mean BMI 24.4 kg/m2) were included in this cross-sectional study. The carbohydrate intake and PA were evaluated by the Brief-type self-administered Diet History Questionnaire and the International Physical Activity Questionnaire, respectively. Participants were stratified into two groups according to whether they were above or below the PA of 1380 MET min/week which is the level recommended by the Japan Diabetes Society and WHO, as well as into tertiles according to their carbohydrate intake. The odds ratio (OR) for obesity (defined as BMI ≥25 kg/m2) in each combined category was determined by a multivariate logistic regression model. The mean daily intake of energy, carbohydrate, protein, and fat was 1695 kcal, 233g, 69g, and 44g, respectively, and the median PA was 1386 MET min/week. ORs for obesity in participants whose carbohydrate intake was in the top tertile (≥ 253g/day) and a PA of &lt;1380 MET min/week compared to those whose carbohydrate intake was in the bottom tertile (&lt; 196 g/day) and a PA of ≥ 1380 MET min/week was 1.8 (95% CI, 1.2-2.9, p=0.01). However, the association became non-significant when adjusted by energy intake instead of the amount of fat and protein.
In conclusion, a daily carbohydrate intake of more than approx. 250 g was significantly associated with obesity in combination with an inactive state in Japanese patients with type 2 diabetes, even though the energy intake might have as strong impact as carbohydorate intake.

Disclosure
S. Matsunaga: None. H. Sone: Research Support; Self; Novo Nordisk Inc., Eli Lilly and Company, MSD K.K., Chugai Pharmaceutical Co., Ltd., Taisho Pharmaceutical Co., Ltd., Takeda Development Center Asia, Pte. Ltd., Daiichi Sankyo Company, Limited, Ono Pharmaceutical Co., Ltd., Kyowa Hakko Kirin Co., Ltd., Sanofi, Kowa Pharmaceuticals America, Inc., Eisai Inc.. K. Tsuda: None. Y. Oshida: None. S. Sasaki: None. J. Satoh: Speaker's Bureau; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Eli Lilly and Company, Kyowa Hakko Kirin Co., Ltd., Mitsubishi Tanabe Pharma Corporation, MSD K.K., Novo Nordisk Inc., Ono Pharmaceutical Co., Ltd., Pfizer Inc., Sanofi, Sanwa Kagaku Kenkyusho Co., Ltd., Sumitomo Dainippon Pharma Co., Ltd., Taisho Pharmaceutical Co., Ltd.. Y. Hayashino: None. R. Nishimura: Speaker's Bureau; Self; Boehringer Ingelheim Pharmaceuticals, Inc., Astellas Pharma US, Inc., Eli Lilly and Company, Abbott, Medtronic, MSD K.K., Novo Nordisk A/S, Sanofi, Takeda Development Center Asia, Pte. Ltd., Kissei Pharmaceutical Co., Ltd., Taisho Pharmaceutical Co., Ltd., Sumitomo Dainippon Pharma Co., Ltd.. N. Tajima: None.