Metabolic Effects of Fasting and Animal Source Food Avoidance in an Ethiopian Adult Cohort.

Fasting is a religious practice to which the faithful comply strictly. The longest period of fasting in Orthodox religion is the lent (in Ethiopia known as "Hudade"). According to the doctrine of Ethiopian Orthodox Christianity, fasters should strictly avoid all animal source foods (ASF) and skip breakfast at least up to lunch time. This can be taken as a well-controlled natural experiment to evaluate the effect of breakfast skipping and avoidance of ASF for 55 days. However, there is no study that evaluated the effect of ASF fasting (avoidance of animal source foods  and breakfast skipping) on lipid profiles, fasting blood sugar and body composition in Ethiopian set up. A retrospective cohort study was carried out among 704 employees of Jimma University (253 fasters and 451 non-fasters) from February 2015 to April 2015. Data on socio-demographic, anthropometry, blood pressure and blood samples were collected according to WHO STEPS procedure. Descriptive statistics and multivariable linear regression models were used to compare the effect of fasting on outcome variables. There was a significant difference in the body fat percent (mean ± sd) between non-fasters (32.35 ± 11.12) and fasters (30.59 ± 11.22, P = 0.045). Similarly, the mean ± sd waist circumference was higher among non-fasters (84.96 ± 11.43 cm) compared to fasters (83.04 ± 11.43 cm, P < 0.033). High density lipoprotein was significantly (P = 0.001) high among fasters (68.29 mg/dl) compared to non-fasters (57.24 mg/dl). Total cholesterol (T.chol) was also higher among non- fasters (181.01 mg/dl) than fasters (173.80 mg/dl, P = 0.035). The mean Triglyceride level was significantly (P = 0.035) high among non-fasters (142.76 mg/dl) compared to fasters (129.39 mg/dl). Similarly, fasting blood sugar was high among non-fasters (100.14 mg/dl) compared to fasters (95.11 mg/dl), P = 0.009. On multivariable linear regression analyses after adjusting for different variables, fasters had a significantly high mean HDL and lower mean T.chol, Triglycerides, FBS and LDL levels. Similarly, fasters had a significantly low mean waist circumference and low mean body fat percent (P < 0.05). In conclusion, animal source food avoidanceand breakfast skipping has a significant desirable health effects on lipid profiles, fasting blood sugar and body composition. The findings imply the need for considering such a dietary practice as a basis for public health promotion. Future research should investigate the effect of ASF fasting and breakfast skipping on micronutrient intake and determine the minimum number of days of fasting required to generate clinically significant effects.