Talking about fat …

 

Photo 1-11-18, 6 17 36 pm

In food and nutrition “fat” or “fats” have various meanings:

  • Fat is a food nutrient.
  • Fats is a food group.
  • Fat is a component in the blood.
  • Fat is a description of body size.
  • Fat is a body tissue.

Confusingly, some writers mix these terminologies up. Even more confusingly, these various meanings of fat can be described by different words and in various ways.

Fat is a macro-nutrient in foods. The macro-nutrients are protein, carbohydrate, fat and (in adults) alcohol. Once digested and absorbed, macro-nutrients provide energy (kilojoules/ calories) to the body for use in various bodily processes. Fat has other functions in the body including cell membrane structure and transport of fat-soluble vitamins. Fats in food can be referred to as “lipids” where lipids are organic substances insoluble in water and soluble in organic solvents. Technically though, food-fats are a sub-class of lipids known as triglycerides. Triglycerides have a glycerol backbone with three fatty acids attached. The fatty acids can be saturated, monounsaturated or polyunsaturated. Food lipids include triglycerides, phospholipids and cholesterol. (1)

Fats” as a food group includes solid fats (butter/ margarine) and liquid oils. This food group contain foods that are comprised almost entirely of fat (the macro-nutrient) with only tiny amounts of protein or carbohydrate (or none), and hardly any vitamins or minerals unless fortified. They are not whole-foods but rather extracted fats from whole foods; such as butter from milk, or olive oil from olives. They are generally not eaten as foods on their own but rather added to foods or used in cooking.

In the 1970s/ 1980s fats was one of the five food groups in Australia. Back then the five food groups were bread and cereals; vegetables and fruit; meat and alternatives; milk & milk products; and fats (butter or table margarine) (2). In the 1990s the five food groups had a major change and became bread & cereals; fruit group; vegetables, legumes; meat, fish, poultry, eggs, nuts, legumes; and (v) milk, yoghurt, cheese. At that time, it was considered nutrients in fats such as Vitamin A could be obtained from other foods, and fats as a separate food group was unnecessary (3).

The most recent (2013) Australian Dietary Guidelines do not include fats as a nutritious food group. However, it considers foods with mainly unsaturated fats (spreads, oils, nuts, seeds, nut butters, avocado) may have ‘health benefits’ (4). The Dietary Guidelines for Americans similarly do not consider fats as a food group but includes monounsaturated and polyunsaturated oils (canola, corn, olive, peanut, safflower, soybean, sunflower) or whole-foods high in these fatty acids (nuts, seeds, seafood, olives, avocados) can form part of a healthy eating pattern (5). Thus, these more recent guidelines group some fatty whole-foods with liquid oils and do not simply group extracted fats.

Both these guidelines, as do many around the world, recommend dietary patterns lower in saturated fat.

Blood fats” are generally referred to as “blood lipids”. They move along in the aqueous environment of the blood attached to proteins as “lipoproteins”. It is postulated some lipoproteins may increase risk and others protect against risk of diseases such as heart disease and Type 2 diabetes. The various lipoproteins doctors test for are described here.

Fat” as a description for body size is considered offensive and stigmatizing. I agree and therefore will not discuss it further in this post.

Fat” is a name for body tissue. There are three main types. Essential fat is required in small amounts in the bone marrow, vital organs, muscles and nervous system; as well as structural components of cell membranes. Storage fat (known as adipose tissue) generally accumulates sub-subcutaneously (under the skin). Ectopic fat accumulates in cells of non-adipose tissue that normally only have small amounts of fat. Accumulation occurs viscerally (around the abdomen) and also may deposit in or around vital organs including muscles, liver, pancreas, and the heart.

This distinction in body fat accumulation is critical as abdominal fat and ectopic fat are considered risk factors for non-communicable diseases such as type 2 diabetes. Sub-cutaneous fat does not bear the same risk. In fact the definition of “obesity by the World Health Organisation is when body fat has accumulated to the extent of having an adverse effect on health. Although body-weight is used as a guide on a population basis (6); for an individual, body-fat distribution is an important consideration. Some people of lower body weight can be at risk of disease (and therefore technically ‘obese’) if they have a tendency to accumulate fat around the abdomen or ectopically. A good guide is waist circumference. Recommendations for Australian adults can be found here.

In 2013 when I was going through my own weight / health / emotional crises … I began to ponder the connections between the different aspects of fat. How did food-fats relate to blood-fats … or body-fat … or disease risk … and why was there this change in food-group categorization where fats fell out of favour and have now come back? Most importantly, what consideration did they have for me as an individual?

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Disclaimer: Nothing in this article or on this website should be taken as medical or dietary advice. Anyone reading any information provided within should seek advice from their own medical practitioner for any issue, disease, illness or health-related problem they may have. Always seek your own advice from a medical practitioner or dietitian before changing your own diet.
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(1) E Whitney, S R Rolfes, T Crowe, D Cameron-Smith, A Walsh. Understanding Nutrition. Australia and New Zealand Edition. 2nd Edition. Cengate Learning. 2014.

(2) Food For Health. National Food Authority. Commonwealth of Australia. 1991

(3) The Australian Guide to Healthy Eating. Background information for nutrition educators. Commonwealth of Australia. September 1998.

(4) National Health and Medical Research Council. Eat For Health: Australian Dietary Guidelines Summary. Canberra: National Health and Medical Research Council, 2013.

(5) Dietary Guidelines for Americans 2015-2020, 8th edition. US Department of Health and Human Services and US Department of Agriculture. December 2015.Available at https://health.gov/dietaryguidelines/2015/resources/2015-2020_Dietary_Guidelines.pdf

(6) Defining Adult Overweight and Obesity. Centers for Disease Control and Prevention. June 16, 2016. Retrieved 21 November, 2018.

A false dichotomy – dietary guidelines and the other diet

Dichotomy (2)
A Dichotomy – Black or White.

A dichotomy is a division into two entirely different and often contrasting domains, interests or activities (1). Examples of true dichotomies are black or white. Tall or short.

A false dichotomy is an argument giving a false illusion of there being only two choices whereas in reality there can be at least one other or even many possibilities (2). The argument is set up in such a way as the first choice is eliminated due to it being seen as a terrible choice, and the only other alternative is the second choice.

Over the last decade dietary guidelines have come under attack. Arguments against them are often presented in the manner of a false dichotomy. These are the steps used in that line of fallacy: Continue reading “A false dichotomy – dietary guidelines and the other diet”

A return to the heart of the matter

Catalyst: a person or thing that precipitates an event.

Heart

In October 2013, the ABC TV in Australia aired a two-part documentary ‘Heart of the Matter‘ on their behind-the-science program Catalyst. The first segment investigated the diet-heart hypothesis and the history behind diet recommendations to eat less saturated fat. The second segment was on use of statin drugs for reducing the risk of heart disease.

This was a topic of great interest to me. My own father had had a heart attack in 1969 at the age of 45 years. He died from a stroke 5 years later at the age of 49. His death had a devastating and lasting impact on my family. For my whole adult life I had striven to avoid heart disease by following what is considered a heart-healthy diet. The Catalyst segment on diet went against some of my firm beliefs as to what is considered a healthy diet for prevention of heart disease.

The show was critical of dietary guidelines to lower foods with saturated fats such as meat, butter and dairy; and base the diet on bread, grains, and cereals. It implied those guidelines put us “in the nutritional mess we are now in” focussing on supposed flawed science that led to the guidelines. It implied saturated fat was not a contributor to heart disease, cholesterol in the blood is nothing to worry about, people have a pre-set cholesterol level you cannot change by diet; and sugar is the real cause of heart disease. It was the first time I had heard such claims from a reputable source (the ABC).

I had some concerns after watching the program. The program did not present any evidence (only opinion) that saturated fat was innocent in regard to heart disease, and no evidence of sugar instead being the supposed cause. It implied promotion of our cereal-based diet was at least part due to marketing from food companies, yet it presented no evidence of any supposed detrimental effects of diets based on cereals or other higher carbohydrate foods. It did not offer any alternative heart-healthy diet. It did not detail the “mess” we were now supposedly in.

The “mess” that was the 1970s

In the 1940s to early 1960s, heart disease was considered a normal part of aging. People grew old in their 60s. In their 70s, they had heart attacks and died. By the mid-1960s, two things had changed. Firstly, it became known younger people could also develop heart disease and could die. Secondly, research showed prevalence rates of heart disease were lower in other countries. With these two pieces of emerging evidence, it was postulated heart disease was not a normal part of aging but some factor to do with the western diet or lifestyle. Health authorities began to recognise that changing diet and lifestyle could have a bearing on the disease. This was a radical change to the way medical authorities had thought and advised up until that time. Did the program (and others since) making the claim that dietary guidelines supposedly drove us into a “mess”, fail to grasp the grave underlying reason dietary recommendations were made in the first place?

Dietary guidelines were issued from the 1970s because we were already in a “mess”

Young people were dying prematurely of heart attacks and strokes. The dietary guidelines did not create the supposed “mess”. Whilst they did not get every aspect 100% correct in the first guidelines, and there have been some revisions since, the guidelines may have contributed to improved trends in heart disease rates. In Australia, there has been a decline in cardiovascular disease death rates >70% since the 1970s (1).

Figure 1. Age-standardised death rates, 1913-2012. Source (2).

Heart-Disease-deaths (2)

Having lived through that era of dietary change and those improved statistics, having lost my own father in 1974 through heart disease in his 40s, it baffled me that something considered pioneering – changing health outcomes by changing diet and lifestyle (which is actually quite sensible) – could be portrayed so negatively decades later.

Fried fatty foods

Another factor that deeply concerned me (in regard to what other people may assume who may have watched the program) were images scattered throughout of fried fatty foods, and the seeming fixation on establishing which type of fat to use for (deep) frying. There were eleven video clips in the half-hour program of sizzling fats frying eggs, bacon, sausages; deep-frying chips; or butter sizzling in a pan.  Was this the supposed alternative heart-healthy diet? Were we supposed to return to eating a lot of fatty and deep-fried foods (as long as the fat we used was saturated fat)? Was this the message? Was it implying frying foods and eating butter were not only not unhealthy, they were actually healthy? If so, where is the evidence? None was presented.

Frying foods was one of the things that had been swept out of my own diet after my father’s heart attack 45 years before … although the fat and the frying had crept back in.

My own catalyst

A few weeks before the program I had my own ‘catalyst’ (7) and at the time Catalyst aired I was midstream following diet advice as promoted on the website of the Australian Heart Foundation (3). Despite the Catalyst program implying such recommendations were based on weak science, flawed and probably would not work (and I note that adding fats and frying foods were two of the things I dramatically reduced), remarkably within ten weeks my total cholesterol had dropped 25%, my LDL cholesterol plummeted 31% and my triglycerides 18% (4). (These components a doctor may test for are described here.) Whilst I could not exactly be sure which foods had which effect (foods I added being beneficial, or foods I restricted being detrimental), changing my diet did make a difference and thus at least one claim on the Catalyst program for at least one person (me) did not hold true – “you cannot change your cholesterol level by changing your diet“. I changed mine. Moreover the changes were based on guidelines of a health advocacy group. Maybe the science and guidelines can be trusted after all.

In case you missed the point I am trying to make, I will repeat it.

Young people were dying in the 1960s and 1970s. Struck down in their prime.

My father was one of them. In remembrance of him and his untimely death, I can no longer let pass opinions given without evidence that imply dietary guidelines were or are responsible for any supposed health ‘mess’, that advocated dietary guidelines are not worth a try, or that include statements that are factually incorrect (5, 6). The guidelines seek to advise how people may improve their own health.

It is time for me to speak up …
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Disclaimer: Nothing in this article or on this website should be taken as medical or dietary advice. Anyone reading any information provided within should seek advice from their own medical practitioner for any issue, disease, illness or health-related problem they may have. Always seek your own advice from a medical practitioner or dietitian before changing your own diet.
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References and Notes:

(1) Australian Heart Disease Statistics 2014. Australian Heart Foundation.
In Australia, there has been a decline in cardiovascular disease death rates >70% since 1970s. This trend is reportedly due to equal measures of both improved survival and lower incidence rates. Lifestyle factors of reduced smoking, exercise and better diet are contributory lifestyle factors. Australian heart disease death rates are lower than in other high-income countries such as USA, UK and Germany, although higher than Japan.

(2) Australian Heart Disease Statistics 2015. Australian Heart Foundation.

(3) The (Australian) Heart Foundation (AHF) is a charity dedicated to fighting heart disease. On their website www.heartfoundation.org.au in September 2013 dietary advice I read was: To lower LDL: eat foods high in soluble fibre (oats, beans, legumes, apples, pears, barley); eat fish two serves a week and omega-3 fatty acids; eat nuts; reduce consumption of saturated fats and trans fats. To raise raise HDL: become more physically active, lose weight, choose healthier fats (mono-unsaturated and omega 3 fats), eat fish and nuts, drink alcohol in moderation.

(4) The actual changes to my diet that I made in that ten week period were to eat more oats, barley, beans and lentils; eat oat bread, less other bread; eat some nuts; swap from 1% milk to skim milk at home, skinny milk when out; drop full-milk coffee lattes; cut out red meat; reduce chicken or fish to twice a week; eat more vegetables; use canola or olive oils when cooking, although I actually cut out added oils and fats almost entirely in this period. As a disclaimer: I rarely consume sugar, and I infrequently consume and did not have any sweet fatty foods in this period (eg cakes, biscuits or ice-cream).

(5) There were some statements factually incorrect for the Australian context such as margarine being laden with trans fat. Trans fats have been largely removed from Australian margarine since the mid 1990s. The dietary pyramid depicted the US pyramid which puts bread and cereals at the base. The Australian Healthy Eating Pyramid had cereals, fruit and vegetables at the base.

(6) The Catalyst program described researcher Ancel Keys comparing heart disease rates in six countries, implying he cherry-picked countries to formulate a hypothesis that formed the basis of our dietary guidelines. The graph shown in the program was from 1953. After his preliminary hypothesis, Keys went on to conduct the seven countries study (including Greece that went against his initial hypothesis); and the dietary guidelines were not introduced for another 25 years.

(7) A few weeks before the program I had my own ‘catalyst’. At a doctors’ check my blood test results revealed my cholesterol was higher than previous levels that had, until a decade before, been remarkably low for 22 years. Over that decade I had experienced several chaotic life events distracting my attention from my health. I resolved to re-focus. By the time Catalyst aired I was midstream in following diet advice as promoted on the website of the Australian Heart Foundation (3). Remarkably within ten weeks my total cholesterol had dropped 25%, LDL cholesterol plummeted 31% and triglycerides 18%. Whilst I could not exactly be sure which foods had an effect, either foods I had more of (oats, barley, beans, lentils, nuts) exerting a cholesterol-lowering benefit, or foods I had restricted (red meat, dairy, and oils) no longer having cholesterol-raising effects, one thing was definite – changing my diet made the difference.

(8) Image by Leonie Elizabeth 22 July 2018.