Everything about oils
The most controversial topic to discuss as there is absolutely conflicting information everywhere . It depends on which club you belong to ? low fat ?high fat .
people making sweeping statements backed with evidence and feel so strongly about whatever they believe in.
For a common person like me it is all so confusing.
One day butter is bad and next day it is the only animal fat that is safe.
One day seed oils are good and next day they are the worst.
Olive oil is elixir of life one day and next day it’s not that good ?
What is true?
What and who should we believe in?
Having spent hours and hours reading up, listening to podcasts and heated debates in conferences – I just needed to make some notes for myself so that I could refer to it in the future in case I forget.
So this is the summary of my notes.
Let's start with the basics.
What is fat ?
Obviously it is one of the macronutrients along with protein and carbohydrate we need to consume through diet.
The main difference is that it is calorie dense .
It has 9 cal/gram ( almost twice as much as in Carbs or Protein). So common sense says you may not need a lot of it.
UK recommended guidelines are
total Fat
Maximum recommended intake:
< 70g per day (for the average adult)
No more than 35% of your total daily energy intake.
🔹 Saturated Fat
Recommended limit:
< 20g per dayTrans Fats ( which are the bad fats every one agrees on that they are bad, thank god!)
Should be kept as low as possible
(ideally under 2g/day or <1% of total energy)
Well, what does it mean in simpler terms like tea spoons of oil ?
How Much Fat is in Oil?
Most cooking oils (olive, sunflower, rapeseed, etc.) are nearly 100% fat, so:
1 tablespoon of oil = 13.5g of fat (approx.)
1 teaspoon of oil = 4.5g of fat
1 ml of oil ≈ 0.9g of fat
Note: 1 tablespoon = ~15 ml, and 1 teaspoon = ~5 ml.
🧂 Examples:
1 tablespoon olive oil (15 ml)
→ ~13.5g total fat
→ ~2g saturated fatSo if your fat comes mostly from oil:
5 tablespoons/day ≈ full daily fat allowance
But most people get fat from a mix of oil, meat, dairy, nuts, etc.
⚠️ Practical Tip:
Even 2–3 tablespoons of oil plus fat from other foods (cheese, meat, milk, nuts, etc.) can easily meet or exceed the recommended daily fat intake.
Is the fat in my diet the same as the fat in my blood ( cholesterol) ?
NO! Your body makes the cholesterol
Surprised . True! your body makes the blood fat like cholesterol, triglycerides using fats and other nutrients from your diet.
Liver makes 75% of the cholesterol in your body. The rest comes from the food we eat.
Some of it is used for energy and some gets stored for later in muscle and fat tissue.
Types of dietary fats
You probably heard about 2 main types.
saturated fats
Unsaturated fats ; This is further divided into mono or polyunsaturated
And there is Trans fats , which is present naturally in some amounts in some fats but is is the artificial trans fats that are bad and banned. These are fats made by hydrogenation process to increase the shelf life of food.
eg : margarine, frozen baked goods inc pizzas, doughnuts, microwave popcorn etc. Luckily the FDA banned them in 2015.
You might have heard saturated fats are bad and unsaturated fats are good until recently but now there is heated debate about that as there is a lot of controversy about effects of seed oils and how saturated fat is not bad and no increased risk of cardiovascular diseases in some studies.
So which is which . ? What is true ?
To add to the conundrum did you know that
All fats have a mixture of saturated and unsaturated fats!
It's just that they have more of one than the other that gives them the name
Ok let's rewind a little lit and go back to the basics again
We have established we need fat as the macronutrient in our diet but why ?
Fat is needed
For nutrient absorption of fat soluble vitamins like A,D,E,K
Fat supports Brain health which has 60% fat and it needs essential omega3 fatty acids for cognition and memory
Fat is necessary for hormone production like testosterone, oestrogen, cortisol etc
Moreover it is the energy source body can burn when needed. Keeps us full for longer and maintain satiety.
Ok Ok we get it !
BUT
Do we need to get it from the above sources ?
Obviously not as our hunter gatherer ancestors were not squeezing oil out of seeds or condensing fat from animals as they were busy hunting !
We can rely on natural sources of fats in diet like
Nuts, seeds, avocado,coconut, meat, eggs as natural sources and go oil free.
But it does need meticulous planning and calculation on a daily basis.
For a mere mortal like me who wants things to be kept simple ,
what is the difference between these fats and why is there so much controversy?
,
Saturated fat- rich in animal fat sources like red meat, butter, Ghee, Lard, coconut oil
If you want to know if a fat is saturated or not - leave it outside at room temperature - It solidifies at room temperature. ( Not in India when the average temperature is 30!)
Saturated fats are fatty acids with no double bonds between carbon atoms.
The carbon chain is “saturated” with hydrogen atoms — meaning every carbon has the maximum number of hydrogens attached.
Why Saturated Fat Is Often Called “Bad”?
Health Concerns:
Saturated fat raises LDL cholesterol (“bad cholesterol”) in blood, linked to increased risk of atherosclerosis and heart disease.
Research evidence:
American Heart Association (AHA), 2017: Recommends limiting saturated fat to reduce cardiovascular risk because it raises LDL cholesterol (Sacks et al., Circulation, 2017).
Meta-analyses (e.g., Mensink, 2016) show saturated fat increases LDL cholesterol compared to unsaturated fats.
Mechanism:
Saturated fats decrease LDL receptor activity in the liver, causing LDL to stay longer in blood.
High LDL promotes plaque buildup in arteries → increased heart attack and stroke risk.
But the increased risk with heart disease is not linear , it is ‘S’ shaped as per some studies . That means risk does increase with moderate to highish doses of saturated fat in your diet then it plateau.Also there is more risk with too little dose as you may be replacing it with too many carbs.
Why Saturated Fat Can Also Be “Good” or Neutral
The relationship between saturated fat and heart disease is complex and may not be as direct as once thought
Some studies show no direct link between saturated fat intake and heart disease when part of a balanced diet.
Research nuances:
The PURE study (2017) found that high saturated fat intake wasn’t strongly associated with heart disease risk, suggesting the role of whole diet context (Dehghan et al., Lancet, 2017).
Increased Carbohydrate Intake When Reducing Animal Fat
Problem: Cutting saturated fat often leads to replacing it with refined carbs and sugars, which may worsen cardiovascular risk.
Evidence:
The Women’s Health Initiative (2006) found no significant heart disease risk reduction from lowering saturated fat when replaced by carbs (Howard et al., 2006).
Ludwig & Willett (2013) showed that replacing saturated fat with high-glycemic carbs raises triglycerides and lowers HDL cholesterol, increasing heart disease risk (Circulation, 2013).
Keto or Carnivore
Saturated fat may not be as harmful in the low-carb, high-fat context of keto or carnivore, as they shift the fuel mechanism to ketones. They may also have reduced inflammation and insulin sensitivity.
But long term data is lacking as most people can adhere to it in the first 6 months but studies show that at 2 years <10-15% maintain it.
Then it can have worsening effects on LDL and insulin sensitivity mixed with carbs.
What's the fuss about unsaturated fats?
Ok by now you can see there are 2 types of unsaturated fats – mono and poly.
What’s the difference?
MUFAS- monounsaturated fats contain one double bond in their carbon chain.
These double bonds affect shape, fluidity, and oxidation stability.
More double bonds = more reactive to heat, light, and oxygen.
Food Sources - Olive oil, avocado, almonds, peanuts, canola oil
MUFA ---- the Good guy everyone at least agrees on this!
Reduce LDL cholesterol
Improve insulin sensitivity
Anti-inflammatory compared to saturated or trans fats
Central to heart-healthy diets (e.g., Mediterranean diet)
A meta analysis on dietary fats and mortality found that
replacing saturated fats with monounsaturated fats was associated with lower all-cause and cardiovascular mortality.
A 5% energy increase from MUFAs in place of saturated fat reduced cardiovascular risk.
It’s also known to reduce LDL and improve insulin sensitivity in some studies.
Mediterranean diet which is rich in olive oil, nuts and seeds is an example of this.
Again whole sources are better and the dose makes the poison.
What Are PUFAs?
Polyunsaturated fatty acids contain two or more double bonds, making them more fluid and biologically active than saturated fats.
There are 2 main types
Omega 3 and omega 6.
Now I got your attention right !
Lets dive into it.
These 2 are essential fatty acids that means our body can’t make them and we need to take them in diet and if we don’t take in adequate amounts there are health consequences.
Omega 3 – rich in oily fish, flax seeds,chia seeds,walnuts,hemp seeds
Omega 6- rich in sunflower oil, canola oil, corn oil,soybean oil etc.
So why is omega 6 getting such a bad press if it is essential and we need to consume it .
Mainly 2 reasons.
The ratio of omega 6 to omega 3 in our diet matters. WHO recommends the ratio to be around 5;1
But because we use so much of the refined oils in our cooking the ratio is more like 15;1 to 20;1
Why Does the Ratio Matter?
Omega-6 (especially linoleic acid) is pro-inflammatory in high amounts.
Omega-3 (EPA, DHA, ALA) is anti-inflammatory and supports:
Brain function
Heart health
Hormone balance
An imbalanced high omega-6:omega-3 ratio is linked to:
Chronic inflammation
Heart disease
Autoimmune conditions
Mental health issues (depression, cognitive decline)
High-PUFA Content = High Oxidation Risk
PUFAs, especially in seed oils, are chemically unstable and prone to oxidation during:
High-heat cooking (e.g., frying)
Industrial processing (refining, bleaching, deodorizing)
Long storage under light/air
Oxidized PUFA products (e.g., aldehydes, oxylipins) can cause cell damage, inflammation, and may contribute to chronic disease.
So again in summary the same theme repeats- It’s the balance of different fats that matter and quantity. Again the Dose makes the poison.
It is the PUFA hidden in crists, biscuits and frozen snacks that is the problem
What about Vegans and their omega3 ?
Consuming 2 portions of oily fish per week should fulfil the requirements of omega 3 for our bodies
But what about vegans- are the plant sources enough with the seeds and nuts .?
While vegans can consume plenty of ALA (alpha-linolenic acid)—the plant-based omega-3—it’s the low conversion rate of ALA to EPA and DHA that poses a challenge.
ALA must be converted in the body to:
EPA (eicosapentaenoic acid)
DHA (docosahexaenoic acid)
...which are the active forms used for brain and heart health.
Conversion Rate Is Low:
ALA → EPA: ~5–10%
ALA → DHA: often <1–4%
But if consumed on a daily basis to build a good base , cut back on omega 6 fats to reduce the ratio, ensure enough Zinc, magnesium, B6 which support the conversion and consider algae oil supplement there shouldn’t be any worry!
Lastly about Trans fats
They are bad and to be avoided
Artificial trans fats are Created by partial hydrogenation of vegetable oils to make them more solid and shelf-stable.
Eg; Margarine and shortening (especially older formulations)
Packaged baked goods (cookies, cakes, crackers)
Fried fast foods (French fries, fried chicken)
Microwave popcorn
Ready-made frosting and snack foods
Luckily WHO Recommendation (2018):
Eliminate industrial trans fats from the global food supply by 2023.
Lastly about Seed oils - Are they really bad ? Can I cook with them ?
Yes they may have more omega 6 content but if having a balanced diet and not using seed oils in the form of ultra processed food , it should be fine .
It is not great at hight temperatures as it oxidises and produces harmful chemicals .
It is shown to reduce LDL cholesterol , so is good
Bottom Line
It’s the dose that makes the Poison.
It’s the total amount of fat consumed on a daily basis that matters rather than which kind.
Even if we avoid heating our seed oils at high temperatures and substitute it with butter or Ghee if the total amount is more than what our body needs or even worse if we consume that as well as excessive carbs- we end up doing more damage .
Remember we need only 5 tablespoons of fat in the diet including the fat that is already present in the whole foods we eat. So what happens to the excess?
1. Excess fat is not burned for energy if calorie needs are already met.
It's converted to triglycerides and stored in adipose tissue (fat cells).
2, Causes Insulin Resistance- as excess fat accumulates in liver and muscle
3.Mitochondrial stress and oxidative stress- leading to inflammation, aging.
AS a result we end up being overweight, high triglcyerides ( high cholesterol) in blood, develop fatty liver, diabetes and other metabolic disorders.
So in summary saturated fats in whole foods are generally better – like nuts , seeds, avocado, eggs and meat.
If you are arguing which fat is better is deep frying- Do not deep fry regularly. But in general saturated fats are better and there are examples of animal as well as plant fats that are saturated.(coconut oil,palm oil)
Do not substitute fats for carbs!
The conversation about fats should be thought and executed at individual levels and ‘ not one size shoe fits all!’
fat intake should be personalized based on age, health status, genetics, and lifestyle
examples- Saturated fat is not inherently harmful for children, especially from whole foods (milk, eggs, meat).
Adults with family history of heart disease- should reduce amount of saturated fat and consider MUFA and PUFA like oilve oil, avocado, fish
people with insulin resistance or prediabetes- may want to reduce saturated fat and reduce carbs and focus on Unsaturated fats like olive oil, nuts, omega3 from whole foods
For a keto dieter ( low carb high fat ) Saturated fat from steak, butter, coconut oil, cheese is less problematic if not combined with refined carbs.
For someone with high cholesterol (genetic/diet related) along with avoiding trans fats and limiting refined carbs consider a diet rich in fruits, vegetables, whole grains, nuts, olive oil, and fish.
For fatty liver disease - limit saturated fats, diet rich in MUFA’s and omega 3 and avoid trans fats Proven to reduce liver fat and improve blood lipid profiles.
After all that summary
Use whole food sources for fat as much as possible. like nuts and seeds,fatty fish, avocado, fish, eggs, dairy ( Moderation), dark chocolate.
If need to use for cooking
🟢 Best for heart health:
Rapeseed, olive, and avocado oils — low in saturated fat, high in good fats.
🟡 Moderate use advised:
peanut oil, sunflower oil — mixed profile.
🔴 Limit intake:
Butter, ghee, coconut oil, palm oil — high saturated fat content.
I do not feel we need to avoid any type of fat completely based on the info above
I do not feel we need to consciously add more of one type of fat either .
But again it has to be adjusted based on so many factors like age, risk factors, current health etc.
Olive oil ,rapeseed oil seem to have all round benefits. It is rich in antioxidants as well as polyphenols and stable for cooking. Avocado oil same profile as well but expensive.
