Guidelines Dietary - Eat For Health

3.1 Limit intake of foods high in saturated fat3.1.1 Setting the sceneContinuing research into diet and cardiovascular disease emphasises reducing saturated fat in the diet, whichmeans limiting intake of foods with high saturated fat content. Fat is a nutrient in food but the term ‘fats’ hasalso been applied to whole foods (e.g. butter, margarine and oils). Foods known as fats can also be ingredientsin other foods (e.g. cakes and biscuits) or added as a culinary adjunct (e.g. oil in cooking or dressings). As anutrient, fat has high energy value (fat delivers about 37 kJ/g, compared to around 17 kJ/g for carbohydrateand protein).The evidence indicates that replacing dietary saturated fat with monounsaturated and polyunsaturated fats isassociated with improved blood lipid profiles and reduced risk of cardiovascular disease. Replacing the type offatty acids in fats requires a total diet approach and is not always possible with all foods. Both the amount andtype of fat need to be carefully considered as all types of fat provide kilojoules and the proportion of total fatin a diet influences energy intake, which may have an impact on weight management (see Chapter 1).As people choose to eat foods, rather than food components or nutrients, the focus of this guidelinerecommendation is on foods containing fats, not fatty acids per se. Information on particular types of fattyacids is included in the NRV Document. 8Most fats in foods are in the form of triglycerides, which are made up of a unit of glycerol combined withthree fatty acids that may be the same or different. The differences between one triglyceride and another arelargely due to the fatty acids attached to the glycerol unit. Other dietary fats include phospholipids, phytosterolsand cholesterol. 8Guideline 3Over time, the understanding of physiological effects and pathways have been gradually refined – for example,with the discovery of low-density and high-density cholesterol and more recently, the discovery of sub-fractionsof these. 664 Additional physiological characteristics are being studied as possible markers of cardiovascular risk(e.g. vascular reactivity and carotid intima medial thickness). It is also apparent that not all fatty acids withineach group have the same effects – for example, stearic acid might not have the same effects as some othersaturated fatty acids (SFAs). 664 However, as a general message to the public, limiting total dietary saturated fatremains the best guide.Fatty acids include SFAs, monounsaturated fatty acids (MUFAs) or polyunsaturated fatty acids (PUFAs). The typeof fatty acid depends on the chemical bonding within the fatty acid molecule, specifically the number of doublebonds between the carbon atoms. This gives fatty acids differing chemical properties that cause differentbiological effects. MUFAs and PUFAs with one or more double bonds in the trans configuration are knownas trans-fatty acids (TFAs). 665 Omega fatty acids (omega-3 and omega-6 PUFAs) are sub-classes of PUFAs.The essential fatty acids (which humans do not make) are considered to be linoleic acid (omega-6 PUFA) andalpha-linolenic acid (omega-3 PUFA). The most common omega-9 fatty acid is oleic acid, a MUFA.Staple foods with a relatively higher fat content, such as nuts, seeds, some grains (e.g. oats), dairy foodsand meats, have various combinations of fatty acids. Fish is the predominant source of two omega-3 LCPUFAs,eicosapentaenoic acid (EPA) (20:5) and docosahexaenoic acid (DHA) (22:6). Grass-fed meat, kangaroo and offalcontain small quantities of these omega-3 LCPUFAs as well as another, docosapentaenoic acid (DPA) (22:5).The NRV Document recommends that: 8• total fat account for 20–35% of energy (kilojoule) intake• total SFAs and trans fats comprise no more than 10% of energy intake• 4–10% of energy comes from linoleic acid (omega-6 PUFA) and 0.4–1% from alpha-linolenic acid(omega‐3 PUFA).Given that total energy intake reflects the sum of the energy value of all foods consumed, food choices andculinary practices can have a substantial impact on whether these fatty acid targets are met. 968EAT FOR HEALTH – australian dietary guidelinesNational Health and Medical Research Council