What You’ll Takeaway -
- Government guidelines of fat consumption at 30% of total energy intake and saturated fat consumption to 10% were made in light of the 7 countries study, by Keys.
Keys, pretty much tailored the results. Only including data to get the results he wanted.
- A recent meta-analysis has sought out to show the current guide lines are not backed by scientific research.
- There is no association between saturated fat and heart disease.
There is no definitive recommendation as to dietary fat intake as everyone’s needs and circumstances are different, however a good guideline to follow would be to consume about 0.3-0.6g of fat per pound of bodyweight.
Back in 1977 (1) and 1983 (2) the US and UK Government guidelines advised reducing dietary fat intake, ‘reduce overall fat consumption to 30% of total energy intake and reduce saturated fat consumption to 10% of total energy intake.’
These guidelines were released to try and prevent the rates of coronary heart disease climbing. The problem was that these guidelines were made in light of the 7 countries study, by Keys. (3)
In 1958, Ancel Keys researched the association between saturated fat and cardio vascular disease, called ‘the 7 countries study.’
The study revealed that the countries that were consuming the most fat also had the highest prevalence of heart disease, which led to the conclusion that dietary fat CAUSED heart disease. This was due to the related levels of total serum cholesterol in the blood.
One massive problem was Keys left out countries that were not eating a lot of fat, but the rate of heart disease was high, and countries where people eat a lot of fat, but have little heart disease.
They also jumped to the conclusion that correlation equaled cause, without looking into the reasons why. He pretty much tailored the results only including data to get the results he wanted.
This study lead to huge Government and media attention having a big influence on the future dietary guidelines.
The media has published work on a recent meta analysis that has claimed the dietary guidelines of saturated fat should never have been released -
‘Fat Guidelines 'Shouldn't Have Been Introduced'
"In a linked editorial, he wrote: "There is certainly a strong argument that an over-reliance in public health on saturated fat as the main dietary villain for cardiovascular disease has distracted from the risks posed by other nutrients, such as carbohydrates.”'
Read more - http://news.sky.com/story/1424508/fat-guidelines-shouldnt-have-been-introduced
‘The trials looked at the relationship between dietary fat, cholesterol, and coronary heart disease. The review found no difference in heart deaths, regardless of whether people were on a high fat or lower fat diet. Professor Iain Broom, of the Robert Gordon University in Aberdeen, said there was now mounting evidence against the introduction of low-fat diets to combat heart disease.’
Read more - http://www.dailymail.co.uk/health/article-2946617/Butter-ISN-T-bad-Major-study-says-80s-advice-dairy-fats-flawed.html
A meta-anaylsis (a statistical technique for combining the findings from independent studies) by Harcombe Z, Baker JS, Cooper SM, et al. in Open Heart, BMJ titled ‘Evidence from randomised controlled trials did not support the introduction of dietary fat guidelines in 1977 and 1983: a systematic review and meta-analysis’ has sought out to show the current guide lines are not backed by scientific research. (4)
They collected data from 6 randomised control trials that were available at the time of the Governmental guidelines being released (1977 and 1983) ‘including study design; participant characteristics; details of intervention and comparison diet; and outcomes relating to all-cause mortality, CHD-related deaths and changes in mean serum cholesterol levels.’
What did they find?
Of all the 740 deaths from the 6 trials, 423 were from coronary heart disease among the 2467 male subjects.
What’s interesting is that 5 of these studies did not test total fat intake at 30% or saturated fat at 10%, the recommended governmental guidelines. So you have to question where the garment got these values from?
[caption id="attachment_3882" align="aligncenter" width="640"]
Fat Guidelines And Dieting Recommendations - Data[/caption]
The 6 trails that were assessed can be seen below -
To quote the results of the paper ‘three studies and the olive oil intervention reported no significant differences in deaths. The corn oil deaths were reported as significantly different, in favour of the control group (0.1>p>0.05).
Leren reported that the difference in all-cause mortality was not statistically significant (p=0.35). The total CHD mortality was 79 out of 206 men in the diet group and 94 out of 206 men in the control group (p=0.097). Woodhill et al recorded 39 deaths in the intervention group and 28 in the control group.
There were 35 deaths from CHD in the intervention group and 25 in the control group. These were described as significant, but not endorsed by statistical analysis.’
What does this mean?
In basic English this means that there was no significant difference in deaths from coronary heart disease between the control groups and the intervention groups from a range of fat intakes.
They found that cholesterol levels within the blood did not correlate with death from coronary heart disease or from another illness. Which to quote the meta-anayalsis ‘undermines the role of cholesterol levels as an intermediate to the development of coronary heart disease.’
Obviously with all research there are certain limitations, but it is the concepts and conclusions that need to be extrapolated and put into context with the majority of other scientific research to understand how it can be related to real life.
The main limitations were that that all the participants were male and the exact details of the quantities of saturated and unsaturated were not known in all bar one of the studies. Only one study detailed the break down of the fats in the intervention and control diet.
Harcombe Z, Baker JS, Cooper SM, et al. concluded that from the literature that was available at the time these dietary guidelines were released by the Government, ‘2467 men had been observed in RCTs.
No women had been studied; no primary prevention study had been undertaken; no RCT had tested the dietary fat recommendations (30% and 10%) and no RCT concluded that dietary guidelines should be introduced.’
Thus is the 30% recommended fat intake, by the US and UK Government, of total energy intake a legit and healthy amount?
Now I do not feel we should be blaming the government and pointing the finger at them saying they have caused ill health and the obesity epidemic as their general guidelines of eating whole nutritious foods, lots of fruit and veg, whole grains, legumes, moderate amounts of dairy and alcohol and less added sugar are great.
The fact is we can not blame the ‘wrong’ recommendations for getting fat. We have gained weight through an excessive amount of calories from all macronutrients and also through less movement.
To be honest how many of us have been eating diligently to the Governmental guidelines?
[caption id="attachment_3883" align="aligncenter" width="420"]
Fat Guidelines And Dieting Recommendations[/caption]
So what other research is there?
Problem is, we like to blame something nutritional for our ill health or rising prevalence of a certain disease. This ultimately takes the blame and responsibility off us.
In a recent article I wrote on saturated fat
I explained that no experimental evidence has ever directly linked, in humans, saturated fat to heart disease. This is just a hypothesis!
This includes a review of 21 studies with a total of 347,747 participants, published in 2010. Their conclusion: there is absolutely no association between saturated fat and heart disease. (5)
Another review published in 2014 looked at data from 76 studies (both observational studies and controlled trials) with a total of 643,226 participants. They found no link between saturated fat and heart disease. (6)
What has been found though is that replacing saturated fats with unsaturated fats reduced the risk of heart disease by 14%. This does not imply that saturated fats are “bad,” just that certain types of unsaturated fats are protective, while saturated fats are neutral. (7)
So how much should I eat?
With all this being said, and myself not being a doctor, I do not suggest you can just go out and eat endless amounts of saturated fat as it has been shown that not all saturated fats are equal (8) and they are calorie rich, and can easily lead to weight gain.
So your food chooses need to be what’s best for you, and get active, going for walks, working out, or going for a bike ride with the family.
For an exact amount I will quote Shredded by Science and Alan Aragon
“There is no definitive recommendation as to dietary fat intake as everyone’s needs and circumstances are different, however a good guideline to follow would be to consume about 0.45g of fat per pound of bodyweight.
This can then be changed on personal preference. Aim to get a good mixture of saturated and unsaturated fats in your diets and avoid consuming mostly one type. Among your consumption of dietary fats should include plenty of omega-3 fatty acids.” – Shredded by Science
“Remember, the amount of fat you want will depend on many specific factors. As a rough goal on a fat loss plan, eat .5 grams of fat for your goal body weight.
Using the 200 pound model, you would consume 100 grams of fat per day, or 900 total calories.
If you find that this is too much and you gain weight (reminder: fat does NOT make you fat), aim for .3 to .4 grams of fat per pound of goal body weight. Listen to your body and you will see changes.”
However, in my opinion you would do better to focus more on you total calorie consumption and physical activity levels, ensuring you are not gaining needles fat mass, which we know has many health implications.
Further Reading -
Cholesterol is NOT the Enemy
The Straight Dope on Cholesterol
Cholesterol, Genetics, & Carbs with Dr. Spencer Nadolsky
- Select Committee on Nutrition and Human Needs. Dietary goals for the United States. 1st edn. Washington: US Govt Print Off, 1977.
- National Advisory Committee on Nutritional Education (NACNE).
A discussion paper on proposals for nutritional guidelines for health
education in Britain, 1983.
- Keys A. Coronary heart disease in seven countries. I. The study
program and objectives. Circulation 1970;41(4 Suppl):I1–8.
- Zoë Harcombe, Julien S Baker,Stephen Mark Cooper, Bruce Davies, Nicholas Sculthorpe, James J DiNicolantonio, Fergal Grace. Evidence from randomised controlled trials did not support the introduction of dietary fat guidelines in 1977 and 1983: a systematic review and meta-analysis. Open Heart 2015;2:e000196.
Patty W Siri-Tarino, Qi Sun, Frank B Hu, and Ronald M Krauss. Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. Am J Clin Nutr January 2010 ajcn.27725.
- Rajiv Chowdhury, MD, PhD; Samantha Warnakula, MPhil*; Setor Kunutsor, MD, MSt*; Francesca Crowe, PhD; Heather A. Ward, PhD; Laura Johnson, PhD; Oscar H. Franco, MD, PhD; Adam S. Butterworth, PhD; Nita G. Forouhi, MRCP, PhD; Simon G. Thompson, FMedSci; Kay-Tee Khaw, FMedSci; Dariush Mozaffarian, MD, DrPH; John Danesh, FRCP*; and Emanuele Di Angelantonio, MD, PhD* Association of Dietary, Circulating, and Supplement Fatty Acids With Coronary Risk: A Systematic Review and Meta-analysis. Ann Intern Med. 2014;160(6):398-406.
- Hooper L, Summerbell CD, Thompson R, Sills D, Roberts FG, Moore HJ, Davey Smith G. Reduced or modified dietary fat for preventing cardiovascular disease. Cochrane Database of Systematic Reviews 2012, Issue 5. Art. No.: CD002137. DOI: 10.1002/14651858.CD002137.pub3.
de Oliveira Otto MC1, Mozaffarian D, Kromhout D, Bertoni AG, Sibley CT, Jacobs DR Jr, Nettleton JA. Dietary intake of saturated fat by food source and incident cardiovascular disease: the Multi-Ethnic Study of Atherosclerosis. Am J Clin Nutr. 2012 Aug;96(2):397-404.