Discussion

Over the decade 2001–2011, improvements in the profile of dietary fats consumed by Irish adults have been observed. However, imbalances in dietary fat quality remain whereby intakes of SFA were higher for all population groups than recommended and with the lowest intakes of long-chain n-3 PUFA for young men and women. Population intakes of trans-fat were within recommended levels. This analysis shows that in 2011 population intakes of total fat (both g/d and %TE), SFA (both g/d and %TE), PUFA (both g/d and %TE) and trans-fat (both g/d and %TE) decreased compared with the previous national food survey in 2001; intakes of MUFA (%TE) increased, whereas no change was evident for EPA and DHA.

Intakes of SFA (13 %TE) by Irish adults in 2011 agree with those reported in other EU countries such as France, Finland or the UK (12–15 %TE)^{( 8 ,} Reference Elmadfa, Meyer and Nowak ^{40 )}, albeit higher compared with other global regions such as North and South America, Asia and Africa where intakes can lie ≤10 %TE^{( 14 , 15 ,} Reference Micha, Khatibzadeh and Shi ^{41 )}. Although a slight reduction of 0·6 % (P<0·001) in mean daily intakes has occurred in Ireland since 2001, average intakes of SFA in Ireland continue to deviate from such numerical guidelines of about 10 %TE^{( 9 )} and from the EFSA guideline of ‘as low as possible’^{( 8 )}. This poses challenges, as despite public health education campaigns and initiatives by the food industry and regulators all population groups were affected, with the lowest levels of compliance (<29 %) with the <10 %TE recommendation^{( 9 )} by older men aged >65 years and men and women aged 36–50 years. Currently, the major food sources of SFA continue to be fresh meats, whole milk and cheeses, as well as meat products and ‘biscuits, cakes, pastries and buns’, which together contribute 40 % to SFA intakes, similar to that reported for other European countries⁽ Reference Pot, Prynne and Roberts ^{21 ,} Reference Linseisen, Welch and Ocke ^{42 )}. Collectively, reductions in the contributions of whole milk and butter to SFA intakes in adults aged 18–64 years (by approximately −6 % from 2001) may reflect public health messages^{( 23 , 43 )} to choose lower-fat options; however, butter remains a greater contributor for older (8·4 %) than younger (5·3 %) adults. Hence, intakes of SFA continue to deviate from current guidance in Ireland. However, this combination of foods contributing to SFA intakes is noteworthy (e.g. milks, meats, biscuits and cakes). Consideration of these differing foods may now be merited in any future dietary guidelines given the growing body of evidence, which suggests differential effects of SFA on health depending on the food form in which they occur⁽ Reference Ericson, Hellstrand and Brunkwall ^{44 )}.

In this study, intakes of trans-fat have decreased by approximately 0·2 % energy in the decade from 2001 to 2011 and, at 0·5 %TE (0·5 %FE), are well below the UK SACN^{( 36 )} recommendation of ≤2 %FE, similar to that reported for Finland (0·4 %TE)⁽ Reference Pietinen, Paturi and Reinivuo ^{20 )}, albeit slightly lower than that reported for the UK (0·8 %FE)⁽ Reference Pot, Prynne and Roberts ^{21 )}. The major dietary sources of trans-fat in the Irish adult diet are now ruminant animal products such as meat, cheese and whole milk (42 % contribution), with decreases observed for foods such as ‘spreading fats and oils’ (from 5·9 to 1·4 % intakes). This is significant given that intakes of trans-fats from animal sources have not been related to CHD events⁽ Reference Micha, Khatibzadeh and Shi ^{41 )} in contrast to those from industrial sources⁽ Reference Linseisen, Welch and Ocke ^{42 )}. It also suggests that commercial foods containing artificial trans-fats are no longer on sale, or at least are no longer consumed to a significant degree, in Ireland.

In general, mean daily intakes of EPA and DHA (269 mg/d) in Irish adults from food and supplements met the EFSA-recommended adequate intake (AI) of ≥250 mg/d^{( 8 )}. Mean daily intakes from food and supplements reported here were in line with mean values published for a sample of Belgian women (276 mg/d)⁽ Reference Sioen, Devroe and Inghelo ^{45 )}, with median values (range 71–228 mg/d) broadly comparable with published median intakes for a representative sample of Belgian adults⁽ Reference Sioen, Vyncke and De Maeyer ^{46 )}. However, median values were higher than those observed for the Dutch National Food Survey depending on age and sex⁽ Reference Van Rossum, Fransen and Verkaik-Kloosterman ^{47 )}. Intakes from food alone were marginally higher in Irish adults; this is perhaps because of the methodology used here, which factored for n-3 content of milks and some meats⁽ Reference Leite, Hearty and Nugent ^{29 )}. Nevertheless, a distribution of intakes was evident in Irish adults, whereby the highest mean daily intakes from all sources were recorded for adults aged >65 years (436 (sd 542) mg/d) and the lowest intakes for men (202 (sd 299) mg/d) and women (161 (sd 240) mg/d) aged 18–35 years. Given the beneficial role of these fatty acids for cardiovascular health and particularly during pregnancy and lactation (where EFSA recommend increasing intakes of DHA by an additional 100–200 mg/d^{( 8 )}), such low intakes by younger subgroups may have implications for longer-term health. Among consumers, supplements contributed up to 55 % of total EPA+DHA intake. Furthermore, the use of n-3 supplements was higher in 2011 (12·5 %) than in 2001 (7·5 %) for all (see online Supplementary Table S2). Upon exclusion of supplement users, levels of compliance with the recommended AI of ≥250 mg/d^{( 8 )} dropped to 85 % of the total population, with lowest compliance (47 %) for female non-supplement users aged 18–35 years. Unsurprisingly, ‘fish, fish products and fish dishes’ and ‘fresh meat’ were the main food contributors in the population, which is similar to the UK⁽ Reference Pot, Prynne and Roberts ^{21 )} and other EU countries⁽ Reference Linseisen, Welch and Ocke ^{42 )}. However, only 52·6 % of Irish consumers (data not shown) eat fish in any form, and in 2011 intake of fish, fish products and dishes was higher in older than in younger adults (data not shown) and in supplement users than in non-users. These patterns were not observed in 2001. This suggests that there is a segment of the Irish population who do not consume fish or fish oil supplements and with inadequate intakes of beneficial long-chain n-3 fatty acids.

In 2011, average population intakes of total fat (34·1 %TE) were within EFSA recommendations^{( 8 )} of <35 %TE based on the practical considerations and evidence from intervention studies, with intakes higher than reported most recently for Finland or the UK⁽ Reference Pietinen, Paturi and Reinivuo ^{20 ,} Reference Pot, Prynne and Roberts ^{21 )}. In 2011, the major contributing food groups to total fat intake were dairy products, fresh meat, meat products and biscuits, cakes, pastries and buns, which is similar to 2001 Irish data and to other EU countries⁽ Reference Linseisen, Welch and Ocke ^{42 )} and the USA^{( 11 )}. Average intakes of PUFA by Irish adults in 2011 met the UK’s recommendation at ≥6 %TE^{( 9 )}, albeit intakes were slightly lower in men of all ages (approximately 5·7 %). Intakes of PUFA by Irish 18–64-year-olds have declined slightly (1 %) since 2001, as has been reported elsewhere⁽ Reference Pot, Prynne and Roberts ^{21 ,} Reference Harika, Eilander and Alssema ^{48 )}. Coupled with the observed reduction in SFA intakes, this suggests that reductions in SFA intakes do not automatically result in an increase in PUFA intakes, as observed elsewhere⁽ Reference Ericson, Hellstrand and Brunkwall ^{44 )}. Of note, replacement of SFA with PUFA, rather than MUFA or carbohydrates, is deemed to prevent CHD and to reduce CHD incidence over a wide range of intakes⁽ Reference Mozaffarian, Micha and Wallace ^{49 ,} Reference de Souza, Mente and Maroleanu ^{50 )}. Hence, any future initiatives to reduce SFA intakes should consider strategies for its replacement.

The strength of this study relates to the quality of the data collected in two national food consumption surveys using estimated and semi-weighed food records, with statistical account given to the differing durations of data recording periods. Particular attention was given to obtaining the most up-to-date fatty acid composition data for foods by availing of updated food composition tables and, as available, analytical data provided by regulatory bodies and the food industry in Ireland. Nevertheless, these data were not available for all foods, and data were not included for the n-6 PUFA; these limitations must be acknowledged. Future studies should estimate intakes of n-6 PUFA to complement the dietary intake data. Other limitations include the self-reported nature of the food diaries, the observational study design and the exclusion of 20–30 % of the original study populations because of their classification as under-reporters. Nevertheless, levels of under-reporting were similar to that reported elsewhere⁽ Reference Pot, Prynne and Roberts ^{21 )}, and their exclusion of under-reporters deemed important to avoid reporting trends based on increasing levels of under-reporting rather than true changes in fat intake, as reported elsewhere⁽ Reference Heitmann, Lissner and Osler ^{51 )}. Levels of under-reporting had increased from 20 % in 2001 to 30 % in 2011, with the profile of under-reporters more likely to be male and slightly older in 2011 than in 2001 (48 % male in 2011 v. 38 % in 2001; mean age 45 (sd 16) v. 42 (sd 12) years). Other limitations relate to intakes of less frequently consumed fatty acid such as EPA and DHA, which may have been underestimated given the short study duration (4 d), where at least 15 d of dietary recording for men and 30 d for women are recommended to account for variations in PUFA intakes⁽ Reference Sioen, Pynaert and Matthys ^{52 ,} Reference Nelson, Black and Morris ^{53 )}. Hence, a true distribution of usual intakes typically requires intake estimates over many days or the use of statistical modelling. Usual intakes were not assessed in this paper; however, by assessing intakes over 4 survey days, this will partly offset any overestimation in the proportion of people above and below the extremes of intake. Nevertheless, this paper provides a comprehensive estimate of dietary fat and fatty acid intakes in Irish adults using up-to-date composition information, which can be used to inform food-based dietary guidelines and public health policy.

In conclusion, improvements in dietary fat intakes in Irish adults were observed with significant improvements in the direction of dietary recommendations during the last decade; however, the possibility remains for improvement in intakes of SFA and PUFA. Future strategies to modulate population dietary fat intakes should consider not only the quantity and quality of fat consumed across the life span, but also the nature of the contributing foods involved and whether replacement strategies are needed when suggesting reductions in intakes of any one fat type.