By Casey Gionet, Alyssa Vriens, and Belinda Ham
In this article, they conducted a study to see if making lifestyle changes would help prevent type 2 diabetes mellitus. The study included 522 individuals aged 40 to 65, who are overweight and have impaired glucose tolerance. The subjects were divided into an intervention and a control group during a six-year period. The subjects were randomly assigned to one of the two treatment groups. The subjects in the control group were given general oral and written information about diet and exercise, but no specific individualized programs were offered to them. The subjects in the intervention group were given detailed advice about how to achieve the goals of the intervention, which were as follows:
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Reduction in weight of 5 percent or more, in total intake of fat to less than 30 percent of energy consumed, and in intake of saturated fat to less than 10 percent of energy consumed
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An increase in fiber intake to at least 15 g per 1000 calories
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Moderate exercise for at least 30 minutes per day
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Frequent ingestion of whole-grain products, vegetables, fruits, low-fat milk and meat products, soft margarines, and vegetables
Each subject in the group also had sessions with a nutritionist, and they also received individual guidance on increasing their level of physical activity. Endurance exercises was recommended to increase aerobic capacity and improve cardio-respiratory fitness. Subjects also performed circuit training to strengthen muscles. Subjects in each group completed a three-day food diary, and nutrient intakes were computed using a program developed at the National Public Health Institute. Oral glucose-tolerance tests were performed annually and the diagnosis of diabetes was confirmed by a second test.
After one year, the mean amount of weight lost was 4.2-5.1 kg in the intervention group and 0.8-3.7 kg in the control group. By two years, the intervention group lost 3.5-5.5 kg and 0.8-4.4 kg in the control group. The cumulative incidence of diabetes after four years was 11 percent in the intervention group and 23 percent in the control group. During the trial, the risk of diabetes was reduced by 58 percent in the intervention group. This study proves that type two diabetes can be prevented by changes in the lifestyle of high risk subjects.
As mentioned on the Etiology and Risk Factors page, lifestyle can be a factor in someone’s chances in developing type 2 diabetes mellitus. After reading this study, it supports that diet and exercise, two modifiable factors mentioned previously, contribute to weight loss which overall had an impact on glycaemic traits. The main goal of this study was to see how different lifestyle factors impact on developing type 2 mellitus diabetes and how each factor is associated to one another. This final analysis consisted the results of 353 participants that made changes in lifestyle factors, including dietary saturated fat, physical activity and weight loss. Body weight, fasting blood and glucose were measured at the beginning to get a baseline and again at the end of the 12 month study. Participants were asked to use a 4-day food diary, measuring portion sizes and average daily intakes of energy, macronutrients, saturated fat and dietary fiber at the beginning for a baseline and again at 12 months.
Significant results included;
Glucose had a moderate improvement for most participants. Unfortunately, not all data could be collected for dietary fiber so this section was eliminated from the study. This study showed that change in weight was an important factor for the change in each factor, creating a common path. Using the example of improvements in glycaemic traits, the study showed that changes in weight, as well as the related changes in physical activity and dietary behaviours, were important for the change in all factors. In patients reducing the amount of saturated fat intake, weight change had a greater impact on glucose then patient that increased the amount of saturated fat intake with weight change. This also connecting to the importance in the quality of diet to maximize reductions in the risk of diabetes. Plasma glucose and insulin was improved but greater improvements were seen in the patients that reduced their saturated fat. Changes in saturated fat and weight loss showed a contribution to changes in insulin sensitivity. Physical activity showed to be only important the path of weight loss. Physical activity has been identified as a factor in preventing diabetes, but in this study, considering it in combination with a number of other factors physical activity was not identified to play a key role in lowering risk of type 2 mellitus diabetes. These results could have been due to measurement errors in this study. Overall this study showed that weight loss and changes in dietary saturated fat were most important factors connected to other factors. The paths of modifiable factors relating to body weight, diet, and physical activity showed to have a greater impact then genetic predisposition on change in glycaemic traits.