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Prevention of type 2 diabetes

Lifestyle changes – in particular, a healthy diet, regular physical activity, not smoking and weight control – can prevent type 2 diabetes and if you already have the condition can greatly help in improving your glucose control. Never underestimate the potential benefits of lifestyle changes both in prevention and treatment (1).

Losing weight and returning blood sugar levels to normal leads to improved beta cell secretion of insulin. Studies in the U.S. have found that people aged 50-71 who led a healthy lifestyle of not smoking, exercising regularly and taking a healthy diet with moderate alcohol and maintaining a healthy weight had a much lower risk of type 2 diabetes than those who did not lead a low-risk lifestyle (2). Lifestyle interventions have also been shown to delay or prevent progression from prediabetes to full-blown type 2 diabetes.

Reducing your weight by even a small amount markedly reduces your risk for developing diabetes and its complications. According to the NHS, a 5% reduction in body weight followed up by regular moderate intensity exercise could reduce your type 2 diabetes risk by more than 50%.

Factors that reduce weight and obesity include regular physical activity (see exercise), eating more polyunsaturated fats and the right kind of carbohydrate and cereal fiber. People incorporating these foods are those who eat a so-called “Mediterranean diet” as in Southern Italy, A key factor in reducing weight or obesity is to maintain a sustainable diet, that is, one that caters to your individual preferences in food and you can incorporate into routine daily life.

Sugary beverages are particularly hazardous to our health as they do not induce satiety and it is easy to over-consume them, leading to increased calories and obesity. Ultimately, it is the number of calories that is important in weight gain.

As adults, we should only ever gain a maximum of 11 pounds and aim to reduce our weight by 5-10% if we are already overweight. Goals for prevention of weight gain and obesity should, therefore, include high-level physical activity, limited television watching, a healthy diet and raising awareness of what constitutes a healthy weight.

Foods that can help you reduce your risk of diabetes

Consuming wholegrains instead of refined carbohydrates has been found to reduce the risk of developing type 2 diabetes. Wholegrains are carbohydrates that are full of nutrients and lead to a more sustained release of glucose, or energy, and this gives us a sense of being full without having a high GI, and can help us consume less. Studies (3) suggest that eating wholegrains, and other energy-dense foods such as nuts, can help in weight reduction.

Polyunsaturated fats such as those in olive oil are associated with decreased insulin resistance (our muscle and liver cells are more sensitive to the glucose-lowering effects of insulin) and a reduced risk of type 2 diabetes.

Coffee also seems to be preventative for diabetes. Numerous studies have found that coffee confers protection against diabetes, with 4 cups a day being found to have a 50% reduction in some population studies. The decaffeinated variety is similarly protective, indicating it is the minerals and antioxidants in coffee which may be important (4). Vitamin D levels may also be important. Our bodies normally produce vitamin D in response to being exposed to sunlight, but for those who are not habitually in the sun, a Vitamin D supplement may be recommended. This is particularly true for obese people, as Vitamin D is fat soluble, and obese people have 30% less Vitamin D than leaner individuals. There is an emerging link between low Vitamin D levels and diabetes risk.

Exercise in prevention and control of diabetes

Regular exercise and avoiding excess body weight are key in reducing your risk of type 2 diabetes (5). People who exercise and have diabetes are often more motivated to closely monitor their diet and blood glucose levels. Some exercise is better than none and additional health benefits are gained as the amount of physical activity increases through higher intensity, greater frequency and/or longer duration. Most health benefits occur with at least 150 minutes a week of moderate-intensity physical activity, such as brisk walking.  Both aerobic (endurance) and muscle-strengthening (resistance training) physical activity are beneficial and the benefits of physical activity far outweigh the possibility of adverse outcomes. Many patients, of course, are limited in their physical activity because of musculo-skeletal problems such as arthritis.

Physical activity can assist with weight control and reduce abdominal fat. In obesity, exercise leads to changes in weight and body composition, with a reduction in fat mass.

The major benefits of exercise in people with diabetes are an increase in insulin sensitivity, reduced body fat, decreased blood pressure, and an overall improvement in the lipid profile (increases in “good” fats, e.g HDL-cholesterol and reduction in “bad fats”).

Walking away from diabetes

Physical activity does not have to be an arduous task. Simply walking for at least thirty minutes a day has been found to lower a person’s risk of developing type 2 diabetes; the longer the walk, the lower the risk. A population study involving over 70,000 nurses found that the women who exercised, significantly reduced their risk of developing type 2 diabetes compared to those who were sedentary (2). Studies also show that if you are sedentary and suffer from type 2 diabetes, taking up walking can initiate a plethora of health benefits, including: a reduction in body weight, waist circumference, fasting plasma glucose (6), HBA1c (7), blood pressure, heart rate, total low density lipoprotein (the “bad” cholesterol), triglycerides, and cardiovascular risk (8). There was also an increase in the good fat, HDL. These health benefits were seen in a diverse range of people of different ages, sex, race, body mass index (BMI), diabetes duration, and physical limitations. The results of this study suggested that in order to experience these health benefits, patients should walk 5K or 45 minutes daily at a pace of approximately 4 miles per hour. Studies suggest that walking after a meal is more beneficial in reducing your blood glucose levels than walking before you have eaten.

However, this amount of walking does not have to be carried out all at once, as it is the summation of the number of steps taken per day which counts. Each step you take impacts your blood glucose levels, and small steps add up, and may put you on the right track for a healthier and longer life.

— May Meleigy


  1. Li G, Zhang P, Wang J, et al. The long-term effect of lifestyle interventions to prevent diabetes in the China Da Qing Diabetes Prevention Study: a 20-year follow up study. Lancet 2008;371(9626):1783-9. doi: 10.016/S0140-6736(08)60766-7.
  2. Reis JP, Loria CM, Sorlie PD, et al. Lifestyle factors and risk for new-onset diabetes: a population-based cohort study. Ann Intern Med 2011;155(5):292-9. doi: 10.7326/0003-4819-155-5-201109060-00006
  3. AlEssa H, Bupathiraju S, Malik V, Wedick N, Campos H, Rosner B, Willett W, Hu FB. Carbohydrate quality measured using multiple quality metrics is negatively associated with type 2 diabetes.  Circulation. 2015; 1-31:A:20.
  4. Shilpa N. Bhupathiraju, An Pan, JoAnn E. Manson, Walter C. Willett, Rob M. van Dam, Frank B. Hu. Changes in coffee intake and subsequent risk of Type 2 diabetes. Diabetologia, online April 24, 2014, DOI 10.1007/s00125-014-3235-7
  5. Tuomilehto J, Lindstrom J, Eriksson JG, et al. Prevention of type 2 diabetes mellitus by changes in lifestyle among subjects with impaired glucose tolerance. N Engl J Med 2001;344(18):1343-50.
  6. Fretts A. M. et al.Modest levels of physical activity are associated with a lower incidence of diabetes in a population with a high rate of obesity. Diabetes Care. 2012 vol. 35 no. 8 1743-1745.
  7. Di Loreto C, et al. Long-term impact of different amounts of physical activity on type 2 diabetes. Diabetes Care. June 2005, Vol 28, no. 6.
  8. Gregg E. W., et al. Relationship of walking to mortality among U.S. adults with diabetes. Arch Intern Med 2003, vol 163, June 23.