1. Introduction
Fat as a macronutrient is needed for humans in relatively large amounts as a source of energy and fatty acids, a heat conserver, a component of cell walls, and a transport vehicle for absorption fat-soluble vitamins A, D, E, and K, which serve as a way of insulating the body and as a shock absorber [
1].
Fats and fatty acids are essential nutrients, but the amount and type of fat consumed have differential effects on health and important implications for chronic disease prevention and treatment [
2,
3,
4,
5,
6,
7,
8,
9]. Studies indicate that the dietary fats have distinct effects on the risk of cardiovascular diseases (CVDs) and incidence of other major chronic diseases, including type 2 diabetes, cancer, multiple sclerosis, and respiratory diseases [
8,
10]. The composition of fat in relation to the proportion of saturated fatty acids (SFAs), polyunsaturated fatty acids (PUFA), and monounsaturated fatty acids (MUFA) is taken into account in the analyses. SFAs are involved in the development of CVDs [
8] and coronary heart disease (CHD) [
3,
4,
5,
6,
7]. Higher intake of saturated and trans-fats was associated with increased risk of CHD, whereas a higher intake of monounsaturated and polyunsaturated fats was associated with a decreased risk [
4]. This is particularly important in the regions where intake of total fat and SFAs are high [
11]. As a result, to prevent chronic diseases, such as CHD, most dietary recommendations focus on the reduction of saturated fatty acids intake [
11,
12,
15]. However, the risk of CHD associated with SFAs varies from no association to a significantly important risk [
3]. WHO/FAO (World Health Organization/Food and Agriculture Organization of the United Nations) expert recommendations for the total fat intake vary between 15 and 30% of the dietary energy, and at least 20% of the total energy delivered from total fat is consistent with good health. For each type of fat, the recommendations for the share of dietary energy are as follows: SFAs <10%, PUFAs 6–10%, of which n-6 PUFAs 5–8% and n-3 PUFAs 1–2%, and trans-fatty acids <1% [
12].
The category of fats and oils includes butter, vegetables oils, margarine, olive oil, and other animal and vegetable fats. Studies suggest that butter consumption increases plasma cholesterol and HDL (High Density Lipoprotein) cholesterol concentration, which ensures that total/HDL cholesterol ratio remains mostly unchanged [
13]. Other results indicate relatively small or neutral associations of butter consumption with mortality, CVD, and diabetes [
2], as well as cancer mortality [
14]. Butter, added fats and oils, and meat and meat products are the three main sources of the total fat and SFA in diets. This is the subject for systematic research due to the fact that the majority of diets in the European population is characterized by increased SFA intake. Data on fatty acid consumption in 24 European countries showed a large variation in fat intake from 28.5 to 46.2% of total energy supply, (SFA from 8.9 to 15.5% and PUFA from 3.9 to 11.3%) [
11].
Based on these arguments, the importance of the total fat intake, as well as individual products from the category of fats and oils in the diet, should be indicated. Therefore, the purpose of our research was to identify food sources of energy and 25 nutrients from the fats and oils category based on the data from the 2016 household budget survey. We also analyzed the impact of socio-demographic and economic factors on the volume of fat and oil consumption, as well as the level and structure of energy and nutrient supply from this food category. This paper is the fifth consecutive article based on the same methodology concerning the sources of energy and nutrients in the average Polish diet. So far, we have analyzed the food sources of protein and amino acids [
15], as well as three groups of food categories (meat, seafood and its products [
16], milk and dairy products [
17], and cereal products [
18]) as sources of energy and nutrients.
2. Methods
2.1. Study Overview
In this study, we analyzed the sources of energy and nutrients from fats and oils in the average Polish diet. The detailed list of these nutrients includes: total fat, fatty acids (saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA)), cholesterol, carbohydrates, protein, 9 minerals (calcium, phosphorus, sodium, potassium, magnesium, iron, zinc, copper, and iodine), and 9 vitamins (vitamin A, vitamin D, vitamin E, thiamin, riboflavin, niacin, vitamin B6, folate, and vitamin B12). We presented the percentage of total fat contribution from other main food categories: meat and meat products, milk and dairy products (including cream), cereal products, snacks and sweets, eggs, seafood, vegetables, and fruits. We also analyzed the impact of socio-demographic and economic factors on the volume of fat and oil consumption and the share of particular products in the supply of energy and nutrients.
The overall test procedure was as follows:
Two-stage random selection of the representative sample of the households (36,886 households), carried out by the Central Statistical Office;
Data collection on quantity of purchase and consumption of food products in 91 sub-groups (in grams, kilograms, liters) per month per household (Central Statistical Office);
Conversion of consumption quantity into one person per month in each household (in grams, kilograms, liters)—our calculations;
Conversion of consumption data into energy and nutrients content (in kcal, g, mg, µg per day) in 91 sub-groups of consumed food products in each household—our calculations;
Calculation of the average energy and nutrients supply in sub-groups in kcal, g, mg, µg per day per person in all households—our calculations;
Calculation of the energy and nutrient contribution from each sub-group (in %) to the average Polish diet—our calculations;
Analysis of impact of socio-demographic and economic factors on the level and structure of energy and nutrient supply from fats and oils—our calculations.
Additional information on the methodology of the Household Budget Survey has been provided in our previous publications on meat, seafood and its products, cereal products, and milk and dairy products, as well as food sources of protein [
15,
16,
17,
18].
2.2. Sample Selection Method
We used data from the household budget survey (HBS), organized and conducted by the Central Statistical Office (CSO), Social Surveys and Living Conditions Statistics Department. The HBS is a representative method of examining households across Poland in terms of many issues related to the consumption of goods and services and their living conditions. In 2016, 36,886 households participated in the survey, which constituted 99,230 people. The procedure for selecting households was a two-stage process, which results from the draw, in the first stage, of the areas survey points, and in the second of specific households in each area survey point. In 2016, during the first stage, 1586 area points were drawn, including 911 area points in cities and 665 in rural areas. Thereafter, households were drawn.
In each household, the volume of purchase of food products to be eaten in the household was recorded in terms of volume (in grams, kilograms, pieces, liters) and value (in Polish zlotys) in a “Household Budget Diary” for one month. Additional information was obtained through detailed interviews in each household based on the “Household’s Statistical Sheet” and conducted by the employees of the regional statistical offices. We used the data obtained by CSO from 36,886 households to calculate the volume of food consumption per person per month [
23,
24].
In 2016, the share of women in the surveyed population was 52.4%. In terms of age, the distribution of the studied population was as follows: 25–34 years (12.6%), 35–44 years (13.8%), 45–54 years (12.5%), 55–64 years (15.8%), and 65 years and above (17.1%). In the study, according to the CSO methodology, four main types of households were included: employees (n = 17,877 households, n = 55,799 people), farmers (n = 1689, n = 6481), self-employed (n = 2500, n = 7970), and pensioners (n = 13,323, n = 25,195). In terms of the number of persons in a household, the structure of the surveyed population was as follows: one-person households (n = 7590, n = 7590), two-person households (n = 12,085, n = 24,170), three-person households (n = 7300, n = 21,900), four-person households (n = 6130, n = 24,520), five-person households (n = 2363, n = 11,815), and six or more-person households (n = 1418, n = 9235).
2.3. Food Grouping
Data on food consumption in households concerned 91 food sub-groups, which, for the purpose of our analysis, were divided into 13 main categories, i.e., meat and meat products; cereal and grain products; milk and dairy products; sugar, sweets, and snacks; vegetables and vegetable products; fruits and fruit products; eggs; seafood; coffee, tea and cacao; nonalcoholic beverages; alcoholic beverages; and fats and oils. A detailed classification has been published in our previous publications [
15,
16,
17,
18]. For the purposes of this article, we have considered fats and oils containing 5 sub-groups:
For this classification, we used a food classification scheme published in literature [
19,
20,
21], with definitions from FAO [
22] and CSO [
23,
24]. These classifications in some cases differ in the recognition of particular types of animal and vegetable fats. For example, FAO defines animal fats as a group consisting of: slaughter tissue fats, rendered fats (lard, in Poland, is traditionally obtained from pigs and poultry, especially from goose), and oils from fish and marine mammals [
22]. According to the CSO, animal fats include butter, bacon, lard, tallow, jowl, and others (raw and rendered). Butter is classified as fresh, melted, and salted and contains up to 20% of vegetable oil. Margarine and other vegetable fats include margarine, vegetable butter, mixtures of butter, and so-called “vegetable butter”, vegetable oils, olive oil, and others [
24].
2.4. Data Analysis
Having quantitative data on the amount of food consumption, we converted them for the supply of energy and nutrients. For this conversion, we applied the latest edition (4th) of the Polish “Nutritive Value Tables for Foods and Meals”) [
25] and the R software environment for statistical computing (v3.0.2) (The R Foundation for Statistical Computing, Vienna, Austria 2018) [
26,
27,
28]. In this way, we received data on the supply of energy and nutrients in each household. Thereafter, we calculated the average energy supply and the average supply of individual nutrients, which was expressed in kcal, g, mg, µg per person per day. This allowed us to determine the share (in %) of each sub-group of food in the supply of energy and nutrients to the average Polish diet.
Subsequently, we analyzed the impact of socio-demographic and economic factors on the consumption of fats and oilsm as well as the level and structure of energy and nutrients supply from fats and oils. For this purpose, we used cluster analysis [
29,
30,
31], using the Neural Networks module in the Statistica 13.3 (Copyright 1984–2917, TIBCO Software Inc., Palo Alto, CA, USA) and the Kohonen Neural Network [
32]. We have divided the sample population into 5 clusters based on 14 factors, characterizing households: education level, income (quintile group), degree of urbanization of the place of household residence, socio-economic type of household, size of the village, usage of agricultural land, self-assessment of financial situation, number of people in the household, region, family life phase, self-assessment of nutrition in household, age, sex, and month of participation in the survey. We calculated the Cramer’s correlation for each feature.
4. Discussion
Fats and oils are a significant source of energy in the average Polish diet, as are the total fats, MUFA, PUFA, SFA, and cholesterol. The purpose of our study was to determine the supply of energy and nutrients from the fats and oils category, taking into account five sub-groups, including butter, vegetable oils, olive oils, margarine and other vegetable fats, and other animal fats. We compared our results with those from other countries, including the United States (2003–2006) [
21], Belgium [
33], Ireland [
34], Australia [
35,
36], Spain [
37], Denmark [
38], and New Zealand [
39], as well as with population nutrient intake goals [
12].
Our research indicated that fats and oils provided 13.2% of the total energy supply to the average Polish diet. Of the five sub-groups of fats and oils studied, vegetable oils were the most important in energy supply (5.7%), followed by butter (3.3%) and margarine and other vegetable fats (3.2%). The data obtained for the average Polish diet are much higher compared to other studied populations [
21,
35,
39,
42]. For example, in the average American diet, vegetable oils and other fats provided 3.6% of the daily energy supply, while butter and margarine provided 2.2% [
21]. Similar results were obtained for the Australian diet (the share of oils and fats in the energy supply amounted to less than 4%, of which margarine accounted for about 2.5%) [
35] and the New Zealand diet (the share of total fat in the energy supply was 3.3%, of which the share of butter and margarine was 3%) [
39]. There was a higher share of fats and oils in the energy supply in the Polish diet, but was only half as much, compared to the average diet recorded in Denmark. In the Danish diet, the share of total fat in the energy supply as 7% [
42].
The high share of energy from fats and oils determines subsequent results, showing the share of this category of food products in the total fat supply, SFA, MUFA, and PUFA. In the supply of total fat, fats and oils accounted for almost 33% of the total contribution. The largest share had oils (almost 14%), followed by margarine and other plant fats and butter (each of these sub-groups were almost 8.5%). In the structure of the total fat supply in the average Belgian diet, the group of fats and oils provided 27.1% of total fat, including margarine at 11.8%, butter at8.9%, vegetable oils at3.3%, and deep frying fats at2.6% [
33]. Studies conducted in the American population indicated the share of oils and other fats in the total fat supply at the level of 9.6%, while margarine and butter accounted for 6.4% of the total fat supply [
21]. Similar figures were recorded for the New Zealand diet: The share of fat in total fat supply was 10.2%, of which 9.3% was recorded for butter and margarine [
39]. In the Australian diet, fats and oils provided less than 12% of the total dietary fat [
35], while in the Danish diet it was 19% [
42].
Fats and oils provided 27.9% of SFA to the average Polish diet. Butter had the largest share, accounting for 13.9% of the supply, followed by vegetable oils (4.8%), as well as margarine and other vegetable fats (4.5%). Similar results were obtained for the average Belgian diet. The share of fats and oils in the supply of SFA was 25%, including butter (13%) and margarines (8.3%) [
33]. In the average American diet, the share of vegetable oils and other fats in the supply of SFA was 8.9%, while margarine and butter contributed 6.3% [
21]. Similar results were obtained for the Australian diet: The share of oils and fats in the supply of saturated fat was 9% [
39]. In the New Zealand diet, the share of edible fats in total fat supply was 8.9%, of which butter and margarine accounted for 8.4% [
39]. A higher percentage of fats in the SFA supply was recorded in the Danish diet at 14% [
42].
Our research indicated that fats and oils contributed 31.5% of MUFA with the largest share of oils (14.2%), margarine and other plant fats (8.1%), and butter (6.1%). The structure of the MUFA supply in the American diet was different: 10.5% of oils and other fats and 6.4% of margarine and butter [
21]. A lower supply of MUFA from fats and oils was recorded for the Australian diet (less than 12.5%), including about 2.5% for milk fats and about 8% for margarine [
35]. In the average Danish diet, the share of fat in the supply of MUFA was 19% [
42], while in the New Zealand diet it was 11% [
39].
In the supply of PUFA to the average Polish diet, fats and oils accounted for almost 46% of all-day contribution. Vegetable oils were the most important (almost 30%), followed by margarine and other plant fats (14.1%). A lower share of fats and oils in the supply of PUFA was found in the average Belgian diet at 32.4%, including margarines at 22.8%, vegetables oils at 3.8%, deep frying fats at 3.3% and butter at 2% [
33]. Similar results were obtained for the average Danish diet, in which fats provided 32% of PUFA [
42]. In the average Australian diet, the share of fats and oils in the supply of PUFA was about 22%, of which margarine accounted for almost 20% [
35]. On the other hand, in the American diet, oils and other fats provided 11.7% of PUFA, while margarine and butter provided 7.4% [
21]. From the nutritional point of view, it would be valuable to calculate the intake of trans-fatty acids in the Polish population. We are not able to show in our study these fat intakes, as the Polish food composition and nutritional value tables do not give their contents in food products. However, the 30 year-long process of creating a modern food market in Poland was accompanied by changes in the food consumption pattern, which is typical for countries in a period of dynamic economic growth. The changes consisted mainly of an increase in the consumption of meat, fats, and highly processed foods [
40]. As a result, the structure of consumption of fats and oils changed. In particular, the consumption of fats and oils of vegetable origin increased 2.8 times and amounted to 24.5 kg/person in 2018 (at the level of food balances based on CSO data). It can be assumed (using our own calculations based on CSO data) that, in this amount, about 9.7 kg are fats used in highly processed foods, including hydrogenated vegetable oils containing trans-fatty acids. Some results indicated that the average intake of trans-fatty acids in Poland is 2.8–6.9 g per day. This means that the intake exceeds the dietary recommendations [
41,
42], according to which the content of these fatty acids in the daily diet should not exceed about 2 g (1% of the energy value of the diet) [
12].
According to our results, fats and oils provided 47.6% of vitamin E, of which 27.7% was delivered from oils and 16.3% from margarine and other vegetable fats. Similar data were obtained for the average Spanish diet, for which oils and fats were the main contributors (45.7%) to the vitamin E intake [
37]. A lower fat content in the supply of this vitamin was found for the Danish and New Zealand diets (24% and 14.2%, respectively) [
39,
42]. The results for the average Polish diet and their comparison with other countries are worrisome for nutrition and health reasons. As shown in
Table 2, fats and oils constituted 1/3 of the total fat supply in the average Polish diet. Therefore, twice as much fat was derived from invisible fats with the highest proportion from the meat and meat products group (31%) and then from the dairy products group (14%, including cream). The consequence of such a fat consumption structure is a high SFA content of 35 g in the diet, which is unfavorable for health, while the MUFA content was 37 g and the PUFA was 18 g (as shown in
Table 4). This amount of SFA constitutes 13.9% of the daily energy supply in the average Polish diet, while WHO/FAO population nutrient intake goals indicate the share of SFA to be below 10% [
12]. Recommended dietary allowances in Poland are even more restrictive, as it is recommended to have 10% of SFA shared in the daily energy supply, only for children aged 1–9 years, and almost twice as low as 5–6% for other population groups. Furthermore, it was stated that the recommended daily intake of SFA should be “as low as reasonably achievable in a nutritionally appropriate diet” [
43]. In the United States, the National Heart, Lung, and Blood Institute (NHLBI), the American College of Cardiology (ACC), and the American Heart Association (AHA) advise lifestyle management recommendations for adults who have elevated low-density lipoprotein cholesterol (LDL–C) intake (which concerns 33.5% of the population). The intension is to reduce the percentage of calories from saturated fat to achieve 5 to 6% of calories from saturated fat [
44]. Randomized controlled trials, that lowered the intake of dietary saturated fat and replaced it with polyunsaturated vegetable oil, reduced CVDs by ca. 30%, similar to the reduction achieved by statin treatment. Prospective observational studies in many populations showed that a lower intake of SFA coupled with a higher intake of PUFA and MUFA is associated with lower rates of CVD and other major causes of death and all-cause mortality [
45]. Improving dietary fat quality by replacement of SFA with n-6 and n-3, PUFA has also a significant influence on the reduction of risk of sudden cardiac death [
46]. Dietary guidelines for Americans in 2015–2020 assumed a shift from solid fats to oils to use oils rather than solid fats in food preparation where possible. This refers to the points: To use vegetable oils instead of solid fats (butter, stick margarine, shortening, lard, coconut oil) in cooking; to increase the consumption of products containing oil naturally; and to choose other foods, such as salad dressings and spreads [
47].
It should be underlined that the share of PUFA in the energy supply in the average Polish diet equaled 7.13% and was close to the lower limit recommended by WHO/FAO experts (6–10%) [
12]. An adequate dietary intake of docosahexaenoic acid (DHA, 22:6, n-3) is particularly important for pregnant and lactating women, children, and adolescents. As the consumption of fish and seafood in Poland is very low, dietary supplementation with DHA is recommended [
43,
48,
49]. However, research carried out in various countries, where the consumption of fish and seafood is higher, also clearly shows this problem. Data from 2003–2008 NHANES (National Health and Nutrition Examination Survey) indicated that US adults did not meet the recommended levels for fish and omega-3 fatty acid intake [
50]. In the case of women, NHANES survey results from the period 2001–2014 showed that a majority of US women of childbearing-age and pregnant women consumed significantly lower amounts of seafood than what the DGA (The 2015–2020 Dietary Guidelines for Americans) recommends, which subsequently leads to low intakes of EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). Moreover, diet supplementation did not eliminate the deficiencies of these nutrients [
51].
The third unfavorable feature concerning fat consumption in Poland was too high a proportion of energy supplied by fats in the average diet compared to the recommendations. It amounted to 38.68% of the daily energy supply, i.e., exceeding WHO/FAO recommendations by almost 9%. This is not only the case in Poland, but it poses the most crucial threat to public health globally, even in developing countries, following so-called western diets and facing different double burden issues [
52,
53,
54]. An increase in the number of overweight and obese people was observed in Poland as well as in other European countries [
55,
56,
57,
58,
59,
60]. In Poland, in 2014, over 62% of adult men weighed too much (44% were overweight and 18% were obese). Among women, the problem concerned over 46% (30% were overweight and 16% were obese) [
61]. Among dietary factors, both total energy supply and fat intake are significantly correlated with body mass index. Moreover, increased intake of fat energy is associated with a greater per unit increase in body mass than the increased intake of energy from non-fat sources [
1]. However, according to a recent Cochrane review [
62], the proportion of energy from fat in food consumed, and its relation to body weight, is not clear. On the base of RCT (randomised controlled trias) results (approx. 54,000 participants), the consistent evidence in adults of a small weight-reducing effect of eating a smaller proportion of energy from fat was found. Simultaneously included cohort studies in children and adults most often did not suggest any relationship between total fat intake and later measures of weight, body fatness, or change in body fatness. However, there was a suggestion that lower fat intake was associated with smaller increases in weight in middle-aged but not elderly adults and in a change in BMI in the highest validity child cohort. Another systematic review and meta-analysis of prospective cohort studies (approx. 89,800 participants) found epidemiological research that pointed to no significant difference in CHD mortality and total fat or saturated fat intake. These findings do not support the present dietary fat guidelines [
63].
Therefore, further research is needed and, at the same time, action to improve public health is important. In Poland, a four-year National Health Program 2016–2020 is being implemented [
64]. The operational objective of the program is to improve dietary patterns, nutritional status, and physical activity of the population. This program is seen as a very important step in the prevention of obesity due to the planning of comprehensive activities supported by the state budget. In previous health programs, there was no specific reference to the fight against overweight and obesity in the Polish society, including children [
65].
The 2016 HBS representative sample size, a consistent approach to classifying food products, and HBS methodology to record purchased and consumed food are strengths of the presented study. However, there are some limitations, particularly the reliance on self-recording of information on consumption in a diary. This can lead to an under- and/or overestimation of consumption data, even though HBS uses well-established procedures to control all recordings. The current edition of “Nutritive Value Tables for Foods and Meals” (4th ed., 2017) includes new products and technological modifications, which may cause difficulties in the comparison of current results with data from earlier years. However, these limitations of the HBS survey are rather typical. Nevertheless, household budget surveys are the only representative method for systematic data collection regarding food consumption in the Polish population.