Editing Fat (section)

==={{anchor|Saturated fat}}{{anchor|Unsaturated fat}}Saturated vs. unsaturated fats===
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Different foods contain different amounts of fat with different proportions of saturated and unsaturated fatty acids. Some animal products, like [[beef]] and [[dairy products]] made with whole or reduced fat milk like [[yogurt]], [[ice cream]], [[cheese]] and [[butter]] have mostly saturated fatty acids (and some have significant contents of [[dietary cholesterol]]). Other animal products, like [[pork]], [[poultry]], [[Egg as food|eggs]], and seafood have mostly unsaturated fats. Industrialized [[baked goods]] may use fats with high unsaturated fat contents as well, especially those containing [[partially hydrogenated oil]]s, and [[processed food]]s that are [[deep-fried]] in [[Vegetable oil#Hydrogenation|hydrogenated oil]] are high in saturated fat content.<ref name="aha2014" /><ref name="husp2014" /><ref name="choo2020" />

Plants and fish oil generally contain a higher proportion of unsaturated acids, although there are exceptions such as [[coconut oil]] and [[palm kernel oil]].<ref name="reec2002" /><ref name="choos2015b" /> Foods containing unsaturated fats include [[avocado]], [[nut (fruit)|nuts]], [[olive oil]]s, and [[vegetable oil]]s such as [[canola]].

Many [[scientific studies]] have found that replacing saturated fats with ''cis'' unsaturated fats in the diet reduces risk of [[cardiovascular disease]]s (CVDs),<ref name="hoop2020e" /> [[diabetes]], or death.<ref name="sacks2017" /> These studies prompted many medical organizations and public health departments, including the [[World Health Organization]] (WHO),<ref name="who2015" /><ref name="who0000" /> to officially issue that advice. Some countries with such recommendations include:

* United Kingdom<ref name="htuk0000xd" /><ref name="nhsuk0000xe" /><ref name="nhsuk2018" /><ref name="nhsuk0000v" /><ref name="bhfuk0000w" />
* United States<ref name="sacks2017" /><ref name="htus2015" /><ref name="usda0000r" /><ref name="cdc2004" /><ref name="USDA2005u" />
* India<ref name="india0000xf" /><ref name="india0000" />
* Canada<ref name="choos2018q" />
* Australia<ref name="ausmd2012" />
* Singapore<ref name="sing0000" />
* New Zealand<ref name="newz0000" />
* Hong Kong<ref name="hong0000" />

A 2004 review concluded that "no lower safe limit of specific saturated fatty acid intakes has been identified" and recommended that the influence of varying saturated fatty acid intakes against a background of different individual lifestyles and genetic backgrounds should be the focus in future studies.<ref name="germ2004" />

This advice is often oversimplified by labeling the two kinds of fats as ''bad fats'' and ''good fats'', respectively. However, since the fats and oils in most natural and traditionally processed foods contain both unsaturated and saturated fatty acids,<ref name="stor1996" /> the complete exclusion of saturated fat is unrealistic and possibly unwise. For instance, some foods rich in saturated fat, such as coconut and palm oil, are an important source of cheap dietary calories for a large fraction of the population in developing countries.<ref name="who2003s" />

Concerns were also expressed at a 2010 conference of the [[American Dietetic Association]] that a blanket recommendation to avoid saturated fats could drive people to also reduce the amount of polyunsaturated fats, which may have health benefits, and/or replace fats by refined carbohydrates — which carry a high risk of obesity and heart disease.<ref name="zelm2011" />

For these reasons, the U.S. [[Food and Drug Administration]], for example, recommends to consume less than 10% (7% for high-risk groups) of calories from saturated fat, with 15-30% of total calories from all fat.<ref>{{Cite journal |last=Nutrition |first=Center for Food Safety and Applied |date=2022-03-07 |title=Health Claim Notification for Saturated Fat, Cholesterol, and Trans Fat, and Reduced Risk of Heart Disease |url=https://www.fda.gov/food/food-labeling-nutrition/health-claim-notification-saturated-fat-cholesterol-and-trans-fat-and-reduced-risk-heart-disease |journal=FDA |language=en}}</ref><ref name="who2003s" /> A general 7% limit was recommended also by the [[American Heart Association]] (AHA) in 2006.<ref name="lich2006" /><ref name="smith2004" />

The WHO/FAO report also recommended replacing fats so as to reduce the content of myristic and palmitic acids, specifically.<ref name="who2003s" />

The so-called [[Mediterranean diet]], prevalent in many countries in the [[Mediterranean Sea]] area, includes more total fat than the diet of Northern European countries, but most of it is in the form of unsaturated fatty acids (specifically, monounsaturated and omega-3) from olive oil and fish, vegetables, and certain meats like lamb, while consumption of saturated fat is minimal in comparison.
A 2017 review found evidence that a Mediterranean-style diet could reduce the risk of cardiovascular diseases, overall cancer incidence, neurodegenerative diseases, diabetes, and mortality rate.<ref name="dinu2017" /> A 2018 review showed that a Mediterranean-like diet may improve overall health status, such as reduced risk of non-communicable diseases. It also may reduce the social and economic costs of diet-related illnesses.<ref name="mart2018xh" />

A small number of contemporary reviews have challenged this negative view of saturated fats. For example, an evaluation of evidence from 1966 to 1973 of the observed health impact of replacing dietary [[saturated fat]] with [[linoleic acid]] found that it ''increased'' rates of death from all causes, coronary heart disease, and cardiovascular disease.<ref name="sydn0000" /> These studies have been disputed by many scientists,<ref name="will2017" /> and the consensus in the medical community is that saturated fat and cardiovascular disease are closely related.<ref name="souza2015" /><ref name="rams2013" /><ref name="rams2016" /> Still, these discordant studies fueled debate over the merits of substituting polyunsaturated fats for saturated fats.<ref name="weyl2015" />

====Cardiovascular disease====
{{Main|Saturated fat and cardiovascular disease}}

The effect of saturated fat on cardiovascular disease has been extensively studied.<ref name="hoop2020e" /> The general consensus is that there is evidence of moderate-quality of a strong, consistent, and graded relationship between saturated fat intake, [[blood cholesterol]] levels, and the incidence of cardiovascular disease.<ref name="sacks2017" /><ref name="hoop2020e" /> The relationships are accepted as causal,<ref name="grah2007" /><ref name="laba2011" /> including by many government and medical organizations.<ref name="who2003s" /><ref name="kris2007f" /><ref name="bda0000" /><ref name="sacks2017" /><ref name="wohf2017" /><ref name="nhsuk0000" /><ref name="FDA2009h" /><ref name="efsa2010" />

A 2017 review by the AHA estimated that replacement of saturated fat with polyunsaturated fat in the American diet could reduce the risk of cardiovascular diseases by 30%.<ref name="sacks2017" />

The consumption of saturated fat is generally considered a risk factor for [[dyslipidemia]]—abnormal blood lipid levels, including high total cholesterol, high levels of triglycerides, high levels of [[low-density lipoprotein]] (LDL, "bad" cholesterol) or low levels of [[high-density lipoprotein]] (HDL, "good" cholesterol). These parameters in turn are believed to be risk indicators for some types of cardiovascular disease.<ref name="fphuk0000" /><ref name="who2003k" /><ref name="irhf0000" /><ref name="usda2010m" /><ref name="cann2007" /><ref name="wohf2017" /><ref name="cata2011" /><ref name="aha0000xc" /><ref name="merck0000" /> These effects were observed in children too.<ref name="sanch2008" />

Several [[meta-analysis|meta-analyses]] (reviews and consolidations of multiple previously published experimental studies) have confirmed a significant relationship between saturated fat and high [[serum cholesterol]] levels,<ref name="sacks2017" /><ref name="clarke1997" /> which in turn have been claimed to have a causal relation with increased risk of cardiovascular disease (the so-called [[lipid hypothesis]]).<ref name="buck1999" /><ref name="lewin2007" /> However, high cholesterol may be caused by many factors. Other indicators, such as high LDL/HDL ratio, have proved to be more predictive.<ref name="lewin2007" /> In a study of [[myocardial infarction]] in 52 countries, the [[apolipoprotein B|ApoB]]/[[apolipoprotein A1|ApoA1]] (related to LDL and HDL, respectively) ratio was the strongest predictor of CVD among all risk factors.<ref name="laba2011n" /> There are other pathways involving [[obesity]], [[triglyceride]] levels, [[insulin resistance|insulin sensitivity]], [[endothelium|endothelial function]], and [[thrombogenicity]], among others, that play a role in CVD, although it seems, in the absence of an adverse blood lipid profile, the other known risk factors have only a weak [[atherogenic]] effect.<ref name="laba2011p" /> Different saturated fatty acids have differing effects on various lipid levels.<ref name="thij2005" />

====Cancer====
The evidence for a relation between saturated fat intake and [[cancer]] is significantly weaker, and there does not seem to be a clear medical consensus about it.

* Several reviews of [[Case–control study|case–control studies]] have found that saturated fat intake is associated with increased breast cancer risk.<ref>{{cite journal |vauthors=Dandamudi A, Tommie J, Nommsen-Rivers L, Couch S |date=2018|title=Dietary Patterns and Breast Cancer Risk: A Systematic Review|journal=Anticancer Research|volume=38|issue=6|pages=3209–3222|pmid=29848668|doi=10.21873/anticanres.12586|s2cid=44149964|doi-access=free}}</ref><ref>{{cite journal|vauthors=Xia H, Ma S, Wang S, Sun G |year=2015|title=Meta-Analysis of Saturated Fatty Acid Intake and Breast Cancer Risk|journal=Medicine|volume=94|issue=52|pages=e2391|pmid=26717389|doi=10.1097/MD.0000000000002391|pmc=5291630}}</ref><ref>{{cite journal|vauthors=Brennan SF, Woodside JV, Lunny PM, Cardwell CR, Cantwell MM |year=2017|title=Dietary fat and breast cancer mortality: A systematic review and meta-analysis|journal=Critical Reviews in Food Science and Nutrition|volume=57|issue=10|pages=1999–2008|doi=10.1080/10408398.2012.724481|pmid=25692500 |s2cid=34098509 |url=https://pure.qub.ac.uk/en/publications/dietary-fat-and-breast-cancer-mortality-a-systematic-review-and-metaanalysis(d733bb2c-2e38-494e-bb66-03b38759e0c2).html}}</ref>
* Another review found limited evidence for a positive relationship between consuming animal fat and incidence of [[colorectal cancer]].<ref name="xxxx2009a" />
* Other meta-analyses found evidence for increased risk of [[ovarian cancer]] by high consumption of saturated fat.<ref name="hunch2001" />
* Some studies have indicated that serum [[myristic acid]]<ref name="mann2003" /><ref name="crowe2008" /> and [[palmitic acid]]<ref name="crowe2008" /> and dietary myristic<ref name="kura2008" /> and palmitic<ref name="kura2008" /> saturated fatty acids and serum palmitic combined with [[tocopherol#Alpha-tocopherol|alpha-tocopherol]] supplementation<ref name="mann2003" /> are [[Prostate cancer#Oils and fatty acids|associated with increased risk]] of [[prostate cancer]] in a dose-dependent manner. These associations may, however, reflect differences in intake or metabolism of these fatty acids between the precancer cases and controls, rather than being an actual cause.<ref name="crowe2008" />

====Bones====
Various animal studies have indicated that the intake of saturated fat has a negative effect on the [[osteoporosis|mineral density of bones]]. One study suggested that men may be particularly vulnerable.<ref name="corw2006" />

====Disposition and overall health====

Studies have shown that substituting monounsaturated fatty acids for saturated ones is associated with increased daily physical activity and resting energy expenditure. More physical activity, less anger, and less irritability were associated with a higher-oleic acid diet than one of a [[palmitic acid]] diet.<ref name="kien2013" />

[[File:Fatchart.svg|thumb|right|Amounts of fat types in selected foods]]