The Effects of Low Glycemic Index (GI) Diet on Cardiometabolic Outcomes Among Obese Chinese Adults

The Effects of Low Glycemic Index (GI) Diet on Cardiometabolic Outcomes Among Obese Chinese Adults: A Randomized Controlled Trial

The aim of this study is to investigate the effects and the acceptability of low GI diet versus a conventional healthy diet on the BMI and other cardiometabolic risk factors of obese Chinese adults in Hong Kong.

29.9% of persons aged 15-84 in Hong Kong are obese. Obesity poses significant detrimental consequences for one's health. Obese patients have an increased risk of mortality when compared with people with normal BMI. Obesity results in arterial hypertension, hyperlipidaemia, heart disease and type 2 diabetes. Low GI diets have been investigated for their impact on weight control. Evidence showed that low GI diets were effective in lowering body mass index. However, the evidence was usually generated from Western populations, thus excluding the influence of Chinese culture on diet.The aim of this study is to investigate the effects and the acceptability of low GI diet versus a conventional healthy diet on the BMI and other cardiometabolic risk factors of obese Chinese adults in Hong Kong.

A prospective, two-arm randomized-controlled trial will be conducted to examine the effect of a low GI diet education program on cardiometabolic outcomes in Chinese adults with obesity. The intervention group will receive a low GI diet education, including a one-off, 60-minute, face-to-face, educational session conducted by the research nurse for GI knowledge input. An informational booklet will be given out during the education session.Three follow-up telephone calls of fifteen minutes will be conducted by the research nurse at the 2nd, 5th , and 8th weeks after completing the face-to-face education session. While the control group will receive an education pamphlets on obesity and balanced diet.Three follow-up telephone calls of fifteen minutes will be conducted by the research nurse at the 2nd, 5th , and 8th weeks after receiving the pamphlets.

At baseline, demographic and clinical data, including BMI, waist circumference, body fat, blood pressure, fasting plasma glucose, HbA1c, lipid profile, 3-day food diary, International Physical Activity Questionnaire (IPAQ-C), and the sense of fullness will be collected.

On the 12th week, data about the BMI, waist circumference, body fat, blood pressure, fasting plasma glucose, HbA1c, lipid profile, 3-day food diary, IPAQ-C, and the sense of fullness and a questionnaire on the evaluation process will be collected.

Inclusion Criteria:

1. BMI >25.0 kg/m2;
2. Waist circumference > 90 cm for men and > 80 cm for women;
3. Aged eighteen years or older;
4. Chinese ethnicity;
5. Can be contacted by telephone;
6. Have the ability to read and understand Chinese; and
7. Can provide informed consent.

Exclusion Criteria:

1. Concurrently participating in any other clinical trials;
2. Concurrently participating in weight control programs;
3. Concomitant intake of weight reduction drugs;
4. Use of calorie restricted diet or specialized diets which contraindicated with low GI diet;
5. Have gastrointestinal problems that would prevent them from following the prescribed diet.