Nutritional and psychological profile of constitutionally thin individuals : a cross-sectional study in a sample of lebanese adults

Abstract

Background: Constitutional thinness is characterized by a low body mass index, the absence of signs of under nutrition and is still misdiagnosed as anorexia nervosa. This rare entity was most often described in European countries. Data concerning their nutritional and psychological profile are missing in other populations or cultures, especially in the Middle East. Objectives: The aim of this study was to assess the psychological, nutritional, and hormonal status in a group of Lebanese constitutionally thin adults in comparison with a control group. Methods: A cross-sectional study was carried out on a sample of Lebanese adults N=52 (25 constitutionally thin of which 20 females (80%) and 5 males (20%), and 27 controls with a BMI between 20 and 25 kg/m2 of which 16 females (59.3%) and 11 males (40.7%) aged 18-35 years. Data was collected on socio-demographic characteristics, anthropometric measurements, psychological status using the Dutch eating behavior questionnaire (DEBQ), nutritional status using 24 hour food recall for 5 days, food dietary intake, energy metabolism and hormonal profile including thyroid stimulating hormone, triiodothyronine, insulin-like growth factor 1 and leptin. Statistical analysis was performed using IBM SPSS Statistics version 20.0. Results: At nutritional level, no significant differences were found between both groups for all absolute values of vitamins, minerals, kilocalories, proteins, carbohydrates, fat, alcohol, saturated fat, monounsaturated fat, polyunsaturated fat, fatty acids intake, dietary fibers, sugar, amino acids except for cholesterol intake which was lower in constitutionally thin individuals when compared to control subjects (182.2 (SD=103.0) vs 254.7 (SD=115.2) mg) (p=0.014). Moreover, both groups had a low intake of polyunsaturated fat and fibers and a high intake of Monounsaturated fatty acids and sugar when compared to reference values. In addition, significant differences were found on meat-lean, meat-very lean and milk-skim with p values of 0.02, <0.001, and 0.028 respectively. At psychological level, both constitutionally thin and control groups were not depressed and significant differences were found between them on restrained and emotional eating but not on external eating. Moreover, no significant differences were observed on socio-demographic, hormonal and clinical levels except for body mass index, skeletal muscle mass, body fat mass and resting metabolic rate. Family income tended to be higher in constitutionally thin. Conclusions: Overall Lebanese constitutionally thin individuals have no under nutrition signs and no food intake deficiencies. Further studies are needed to confirm the low intake in cholesterol and polyunsaturated fatty acids. However, psychological scores confirmed a lack of food restriction. The link between a higher family income and constitutionally thin phenotype needs further sociological approach.