Benefits of dietary intervention extend beyond weight loss
MedWire News: The benefits of a structured and monitored dietary intervention for overweight individuals, and especially those with Type 2 diabetes, may extend beyond weight loss per se, suggest findings of a study published in the journal Nutrition.
The researchers say that prolonged adherence to either a low-fat, Mediterranean diet or a low-carbohydrate diet is associated with favorable changes in biomarkers of lipids, inflammation, liver enzymes, and glycemic control among overweight individuals (body mass index [BMI] >27 kg/m2).
Furthermore, they also observed additional, specific favorable intercorrelations among the biomarkers in patients with Type 2 diabetes, suggesting that the cross-talk induced by the diets is stronger in these patients.
Rachel Golan (Ben Gurion University of the Negev, Beer-Sheva, Israel) and co-authors used data from the rapid weight loss (0-6 months) and weight-maintenance/regain (7-12 months) phases of the Dietary Intervention Randomized Controlled Trial (DIRECT).
DIRECT included 322 overweight men and women who were aged between 40 and 65 years. All participants were randomly assigned to a low-fat, Mediterranean or a low-carbohydrate dietary intervention.
After 2 years of follow-up, the researchers found similar improvements in metabolic parameters, such as significant decreases in weight, insulin, and leptin, for all individuals.
However, participants with Type 2 diabetes (n=46) showed significantly greater increases in high-density lipoprotein (HDL) cholesterol (9.41 vs 6.57 mg/dl [0.24 vs 0.17 mmol/l]) and decreases in the ratio of total/HDL cholesterol (1.28 vs 0.80) compared with those without diabetes. This was despite a trend toward a lesser decrease in waist circumference in the diabetes group (2.1 vs 4.0 cm), notes the team.
In all participants, Golan et al observed significant intercorrelations within the lipid biomarkers assessed. For example, changes in triglycerides were negatively associated with changes in low-density lipoprotein (LDL) and HDL cholesterol, while HDL and LDL cholesterol correlated positively with each other. Increases in HDL cholesterol and apolipoprotein A1 (apoA1) were also associated with decreases in high-sensitivity C-reactive protein.
However, exclusively in participants with Type 2 diabetes, decreases in triglycerides were further associated with decreases in apoB100 and liver enzymes, while decreases in fasting glucose were significantly associated with decreases in LDL cholesterol, apoB100, and alanine aminotransferase. These changes were apparent even during the weight-regain phase, note the researchers.
"We believe this observation emphasizes the potential important benefits persons with diabetes may gain by adhering to dietary regimens irrespective of the degree of weight loss," concludes the team.
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By Nikki Withers