A fat lot of good: balance and trends in fat intake in children with cystic fibrosis

Abstract

Background: The fundamental nutritional treatment of a high fat diet for cystic fibrosis (CF) is established and essentially unchanged in the last 25 years. However, recent concerns have emerged regarding the potential risks of such a diet. We investigated the diets of children with CF to determine the source of energy, energy imbalance, and changing trends of fat intake.

Method: In a prospective longitudinal study over 8 years at a single paediatric CF clinic three-day food diaries that included supplementary nutrition (SN) either as enteral feeds or oral nutritional supplements (ONS), were analysed annually. Influence of year on percent energy by type (fat, carbohydrate and protein) and on fat component: saturated (SFA); monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA) was examined.

Results: 136 food diaries were analysed in 27 children (age range 1-18 years). 51 (37%) food diaries included SN (enteral feeds n=15 and ONS n=36). Mean energy intake was 1726 Kcals (oral diet alone) and 2245 Kcals (including SN). Percent energy from macronutrients did not change significantly over time (protein p=0.06; carbohydrate p=0.44; fat p=0.07) and remained within recommended levels. Mean caloric contribution from fat was 38.7% from oral diet alone and 37.8% including SN. Percent energy derived from SFA remained statistically unchanged (SFA p=0.57) but fell from MUFA (p=0.05) and PUFA (p=0.004). Mean SFA consistently contributed >134% (mean 158%) of reference nutrient intake and mean PUFA intake <100% (92%).

Conclusion: Macronutrient intakes did not change significantly in our population of CF children, but there was a consistent imbalance of fat-sources with over-dependence on saturated fats which, in the context of increased survival in CF may potentially increase risk of cardiovascular disease. Further studies are needed to confirm our findings, investigate consequences of fat imbalance and guide clearer advice regarding appropriate proportions of sources of fat for CF patients.