Veg good, meat bad: Dietary patterns determine pre-diabetes risk, study finds.
Findings from a study involving 150 pre-diabetic subjects and 150 healthy controls identified two distinct dietary patterns.
One emphasised the consumption of vegetables, fruits and legumes (VFL) and the other had a heavy sweet, solid fat, meat and mayonnaise (SSMM) emphasis.
The team from the University of Iran found that after adjusting for age, education, physical activity, BMI and energy intake, the VFL dietary pattern was negatively associated with lower pre-diabetes.
On the other hand the SSMM dietary pattern was positively associated with pre-diabetes.
Focus on diet not nutrients
Whilst the news is not unexpected, the findings add weight to the notion that diabetes can be prevented through lifestyle and dietary changes in those who are at high risk of type 2 diabetes.
The researchers believe focusing on dietary patterns and establishing how they relate to chronic diseases provides a more effective approach than the condition’s link to nutrients.
“People do not make use of the concept of nutrients and food separately,” the researchers noted.
“Nutrients of different foods may have synergistic or interactive effects on each other and it is easier to educate subjects on dietary patterns.”
Here, researchers used a matched case–control study design, enrolling 300 individuals (150 pre-diabetic patients).
These subjects were all below the age of 30 and were considered at high risk of developing type 2 diabetes due to being either overweight or obese, having a family history of diabetes or at least two symptoms of diabetes.
Body measurements were then taken. This included weight, height, waist circumference (WC) and systolic and diastolic blood pressure. Physical activity was also assessed using a questionnaire
Blood samples were then collected after an overnight fast of at least 8 hours for fasting blood glucose (FBG) measurement. Dietary assessment was also carried out via a questionnaire.
“As well as an inverse and direct relation to pre-diabetes morbidity observed in VFL and SSMM dietary patterns respectively, we also found the VFL dietary pattern was inversely related to weight, WC, body mass index (BMI), energy intake, diastolic blood pressure, FBG and 2-h oral glucose tolerance test (OGTT),” the study said.
“Furthermore, the SSMM dietary pattern was positively associated with weight, WC, BMI, systolic and diastolic blood pressures, FBG and 2-h OGTT.”
The study’s findings are in keeping with findings observed in previous research. A study found that impaired glucose tolerance (IGT) was linked strongly to dietary patterns that included urban living, lower physical activity and higher intake of animal food and soya beans as commonalities.
Likewise, a meta-analysis of 10 large studies showed that adherence to a healthy dietary pattern was associated with reduced risk of developing type 2 diabetes.
In addition, the often-mentioned Mediterranean diet showed effectiveness in diabetes prevention in individuals with high cardiovascular disease risk.
“The positive relationship found between the SSMM dietary pattern and pre-diabetes could be a result of high intakes of foods such as red meat, processed meat and animal fat,” the researchers theorised.
“Likewise, the high intake of whole grains, legumes, vegetables and fruits containing high fibre, owing to their low energy content and high satiety effect, may decrease food intake and weight gain,” they added.
The researchers were also keen to note the limitations of this study that included dietary patterns obtained from food intake patterns using a questionnaire. The team pointed to a strong possibility of error because the information collected depended largely on recall.
Factor analysis was used to identify the dietary patterns and, as such, food categorisation was vulnerable to change based on the scientists' research interest.
Source: British Journal of Nutrition
Published online ahead of print: doi.org/10.1017/S0007114516002634
“Healthy and unhealthy dietary patterns are related to pre-diabetes: a case–control study.”
Authors: Gity Sotoudeh et al.