This document discusses the history of recommendations to reduce saturated fat and consume polyunsaturated vegetable oils instead. It summarizes the evidence that led to this shift in the 20th century, spearheaded by Ancel Keys' diet-heart hypothesis. However, more recent randomized controlled trials and meta-analyses find no association between saturated fat consumption and heart disease risk. The document also explores the potential negative health consequences of long-term high vegetable oil and carbohydrate consumption, including increased risk of cancer, obesity, diabetes and heart disease. It argues that animal fats may be healthier than industrial vegetable oils and that reducing carbohydrates can help manage insulin levels and heart disease risk factors.

1. RECONSIDERING FAT
by, NINA TEICHOLZ
Science Journalist
Author, The Big Fat Surprise,
Named #1 Science Book of 2014 by The Economist

2. Vegetable oils (polyunsaturated)
Animal fats vs. Vegetable fats
20th century

3. 0
2
4
6
8
10
12
1909
1918
1927
1936
1945
1954
1963
1972
1981
1990
1999
Shortening
Butter
Lard
Margarine
Beef Tallow
Fat Consumption in the US 1909-1999

4. 0
2
4
6
8
10
12
14
Soybean
Cottonseed
Corn
Olive
Coconut
Vegetable Oil Consumption in the US 1909-1999

6. How it All Started…
RATE OF HEART DISEASE
PER 100,000 PEOPLE
1900
1955

7. Ancel Keys’
Diet-Heart Hypothesis
Saturated Fat/
Cholesterol
(in the diet)
Raised
cholesterol
(in the blood)
Heart Attack

9. 1961: American Heart Association recommends
Polyunsaturated oil to fight heart disease
1980: USDA Dietary Guidelines

10. Trying to prove Ancel Keys’ hypothesis
• Randomized, Controlled Clinical Trials
(gold standard of evidence)
• >10,000 men and women, in experiments lasting 1 to 12 years.
• Conclusion: None of these showed that saturated fats had an effect on
cardiovascular mortality.

11. Ancel Keys’
Diet-Heart Hypothesis
Saturated Fat/
Cholesterol
(in the diet)
Raised
cholesterol
(in the blood)
Heart Attack

12. Data on Saturated Fats Now Being
Rediscovered, Reconsidered
In last 5 years, 14 meta-analyses and systematic reviews looking at:
link between saturated fats and heart disease.
Taken together, these conclude that:
• Saturated fats are NOT ASSOCIATED WITH heart disease
• Saturated fats have NO EFFECT ON cardiovascular mortality (1
review shows polys better)

13. What are the “externalities” of
having swapped animal fats
for vegetable oils?

14. Vegetable oils an industrial product
Vegetable oils (polyunsaturated)

15. Negative health consequences of
vegetable oils
1. Cancer
LA Veterans Study
Rates of Cancer
Group eating
vegetable oils

16. Negative health consequences of
vegetable oils
2. Oxidation, Inflammation

17. What are the “externalities” of
having swapped animal foods for
grains, plants?

18. 0
10
20
30
40
50
60
1965 1971 2011
Carb s up by 30+ %
Fat down by 25 %
Saturated fat down by 17%
Major macronutrient shift in US
1965-2011
Source: Cohen et. al., Nutrition, 2015
1970-2005:
Grains up by 41%
Wheat up by 21%
Fruit up by 13%

19. How Carbohydrates Make you FAT

21. Path to Type 2 Diabetes
(constant exposure to insulin over time)

22. Heart disease risk factors worsened by
excessive carbohydrates
• HDL consistently drops
• Triglycerides often rise
• Small, dense LDL increases (story is more complex than just LDL-C)

23. Negative Externalities
of a high-carbohydrate diet,
based on vegetable oils
•Cancer
•Obesity
•Diabetes
•Heart disease

24. Why Animal Fats are Needed
• These are the natural, whole foods that one can eat to have a
higher-fat, healthier diet (vs. industrialized vegetable oils)
• Returning to animal fats would mean you wouldn’t have to use
palm oil