Adherence to a Mediterranean diet and long-term changes in weight and waist circumference in the EPIC-Italy cohort

Claudia Agnoli,Melania Assedi,Sabina Sieri,Maria Concetta Giurdanella,Salvatore Panico,Giovanna Masala,Vittorio Krogh,Fulvio Ricceri,Amalia Mattiello,Maria Teresa Giraudo,Rosario Tumino

doi:10.1038/s41387-018-0023-3

Abstract

Excessive calorie intake and physical inactivity are considered key determinants of the rapid worldwide increase in obesity prevalence, however the relationship between diet and weight gain is complex. We investigated associations between adherence to a Mediterranean diet and long-term changes in weight and waist circumference in volunteers recruited to the Italian section of the prospective European Prospective Investigation into Cancer and Nutrition (EPIC). We investigated 32,119 cohort members who provided anthropometric measures at recruitment and updated information on recall a mean of 12 years later. Adherence to a Mediterranean diet was assessed using the Italian Mediterranean Index (score range 0–11). Associations between index score and weight and waist changes were assessed by multivariate linear regression models. Risks of developing overweight/obesity and abdominal obesity were investigated by multivariate logistic models. Increasing Italian Mediterranean Index score (indicating better adherence) was associated with lower 5-year weight change in volunteers of normal weight at baseline (β −0.12, 95% CI −0.16 to −0.08 for 1 tertile increase in score), but not in those overweight/obese at baseline (P interaction between Index score and BMI 0.0001). High adherence was also associated with reduced risk of becoming overweight/obese (OR 0.91, 95% CI 0.84–0.99 third vs. first tertile); smaller 5-year change in waist circumference (β −0.09, 95% CI −0.14 to −0.03 for 1 tertile increase in score); and lower risk of abdominal obesity (OR 0.91, 95% CI 0.84–0.99 third vs. first tertile). Adherence to a traditional Italian Mediterranean diet may help prevent weight gain and abdominal obesity.

Highlights

In the three decades or so up to 2013, the global prevalence of overweight and obesity rose by about 28% in adults and 47% in children, from 857 million in 1980 to 2.1 billion in 20131
High score on the Italian Mediterranean Index was associated with lower gain in waist girth and lower risk of abdominal obesity
These associations were marginally influenced by specific components of the Mediterranean diet

Summary

Introduction

In the three decades or so up to 2013, the global prevalence of overweight and obesity rose by about 28% in adults and 47% in children, from 857 million in 1980 to 2.1 billion in 20131. Data from the National Health and Nutrition Examination Survey indicate that between 1999 and 2008 the prevalence of abdominal obesity in the United States increased by about 6% in men and women. General and abdominal obesity are both associated with increased mortality and incidence of chronic diseases. In strictly logical terms obesity arises when calorie intake remains in excess of calories expended for an extended period. The excess has been estimated as substantial (400 kcal/d) in the United States and is considered due to dietary patterns involving energy overconsumption, as well as increase in sedentary lifestyle.

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