Cholesterol: When to worry and what to do about it

Cholesterol can be a confusing topic, especially for the low carb and keto community.   

But for most people, it doesn’t need to be that complex.  Your body does a pretty good job of using the fuels you give it.  

  • If you eat more carbs, you will likely see lower cholesterol and higher blood sugars.  
  • If you get more of your energy from fat, you might see lower blood glucose levels and higher cholesterol.  

But if you fall outside the standard reference range, your doctor may encourage you to take a statin drug to lower your cholesterol.  This leaves many people confused and concerned about the undesirable side effects of statins.

We are usually told that high cholesterol is bad and low is good.  But, like most things in nature, optimal rarely occurs at the extremes.  As shown in the chart below, either too little or too much cholesterol can be a problem.

I usually don’t get caught up in debates over cholesterol.  But, I had the pleasure of meeting Dr Paul Mason at Low Carb Down Under on the Gold Coast, who gave this presentation before my talk on satiety.  If you’re one of the many people who are confused about cholesterol, this is well worth the time!


This article contains:

  • a summary of Dr Mason’s presentation to help you understand whether you need to be concerned about “high cholesterol”,  
  • a cholesterol calculator to determine if you are at risk, and   
  • simple action steps to help you optimise your diet.  

The straight dope on cholesterol

Cholesterol carries energy in your bloodstream for use by your cells.  Your liver tightly regulates the flow of energy from your food and storage to ensure you have just enough.  

While we typically carry around five grams (20 calories worth) of energy in the form of glucose, we have about sixteen grams (150 calories worth) of fat in our blood.  

As cholesterol particles drop off their cargo of energy, they transform from VLDL to IDL, to LDL (i.e. very-low-density lipoprotein, intermediate-density lipoprotein and low-density lipoprotein).

Low-density lipoprotein (LDL) is often thought to be the “bad cholesterol”.  However, this isn’t always the case.  It depends on the company it keeps.  

Like your children when they hang out with the naughty kids at school, LDL becomes “bad” when it becomes oxidised after hanging around in the bloodstream with high levels of glucose for too long.  

We get higher levels of “small dense LDL” particles when they become damaged by glycation (due to the presence of glucose) followed by oxidation (rusting).  It’s likely that high LDL cholesterol isn’t a significant concern unless you also have elevated blood sugars.  

Cholesterol particle size distribution

The cholesterol particle size distribution plot shown below is from someone who has a healthy, non-oxidised LDL profile.  We see a big curve towards the left (below the LDL particle) with a smooth and even distribution.  

However, the cholesterol particle size distribution plot of someone with small dense (glycated) LDL is different.  Rather than a big smooth curve, we see several separate, distinct peaks (yellow, orange and red).   

It’s the oxidised LDL that causes the build-up of plaque (i.e. atheroma) in the lining of our blood vessels which is thought to lead to blockages in the arteries.   

As shown in the chart below, this increase in oxidised LDL precedes the development of lesions in the blood vessel wall, which appears to drive heart disease.  

So, to summarise:

  • if your blood glucose levels are low, then high LDL may not be a significant concern, but  
  • if your blood sugars AND your LDL is high, you may have a problem.   

What should my blood sugar be?  

Testing your blood sugar in the morning before you eat can give you a good understanding of your metabolic health and overall risk.  The lowest overall risk of dying from any cause aligns with a fasting glucose of less than 100 mg/dL (or 5.6 mmol/L).  

Keep in mind that it’s not just a matter of minimising your rise in blood sugar after meals that matters.  Most people on a low carb diet will have reasonably stable blood sugars already.  The data from people using Data-Driven Fasting indicates that there is no relationship between more stable blood sugars and a lower waist:height ratio and BMI.  

It’s your blood sugar before meals that has the strongest correlation with waist:height ratio and your BMI.  

It’s your blood sugar BEFORE you eat (not the rise afterwards) that is correlated with your waking glucose and your blood sugar levels across the day.  

Achieving lower blood sugars and reducing insulin across the day is a matter of gaining a better body composition (i.e. less fat and more muscle) rather than merely decreasing carbohydrates even more.  

When do I need to worry about my cholesterol?

While advanced lipid particle size distribution tests are interesting, they are expensive and hence not regularly performed.  You can quickly tell whether you have a high-risk cholesterol profile based on your routine lab tests using your triglycerides and HDL.  

As shown in the slides from Dr Mason’s presentation:

  • If your triglycerides are less than 0.5 mmol/L (or 19 mg/dL), you have a low risk of having oxidised LDL.  
  • If your HDL is higher than 1.5 mmol/L (or 58 mg/dL), then you likely have a healthy “Pattern A” profile without significant risk of oxidation.  
  • Finally, we have the triglyceride:HDL ratio, which is a well-accepted marker for insulin resistance.  If your ratio of triglyceride to HDL is less than 0.8 (in Australia, NZ or the UK) or less than 1.8 (for the US or Europe), then it’s highly likely you have a healthy “pattern A” cholesterol profile.  However, if your triglyceride:HDL ratio is higher than 1.8 in Australia or UK (or greater than 4 in the US and Europe) you may have cause for concern.

The figure below shows the trig:HDL ratio vs the amount of intermediate and large LDL (open squares) and small dense LDL (black squares) (reference).

  • If your trig:HDL ratio is low, then you likely have a healthy pattern A cholesterol particle size distribution with minimal oxidised HDL (green area).  
  • If you have a high trig:HDL ratio, then you almost certainly have a “bad” pattern B cholesterol profile (red area).  
  • If you sit somewhere in between the two (white area in the chart below), you should pay attention to your blood sugars to minimise the risk of oxidised LDL.  You may even want to go to the effort of getting some more advanced testing (e.g. LDL particle size distribution, apoB or Coronary Artery Calcium Score) to understand your risk better.

Cholesterol Risk Calculator

To help you make sense of this, we have set up a simple spreadsheet.  If you have your triglyceride and HDL numbers from your latest blood test handy and want to check your risk then, you can use this calculator .  Just enter your triglyceride and HDL value to see if you have cause for concern.   

What does this mean for my dietary choices?

The common theme in all of this is that we just don’t do well when we mix high levels of fat and carbs.  It’s not necessarily the fat or the carbs, but rather the combination of the two in the diet and the bloodstream that becomes problematic!  

When we combine fat+carbs in ways that rarely occur in nature, we get cholesterol and glucose hanging around together in our bloodstream for extended periods, which leads to oxidised LDL and eventually heart disease.  

In nature, fat, carbs and protein tend to oscillate with the seasons.  Before modern agriculture and food processing, we wouldn’t have had access to high levels of carbs and fat at the same time.  

We see the same pattern with carb intake vs satiety.  It’s not necessarily the high carb or low carb diet that is problematic, but rather the combination of carbs+fat that leads us to eat more than we need, which causes our body fat stores to be overfull and with a subsequent overflow of high levels of energy into our bloodstream (i.e. fatty acids, blood sugar and ketones).  In our modern food environment, the combination of non-fibre carbs with fat with minimal protein drives us to eat more than we otherwise would.  

The best cholesterol risk indicator

So to summarise, we’ve seen that your risk of heart disease will be lower if your blood sugars are lower.   While stabilising your blood sugars is an essential first step (i.e. your blood sugars should rise by less than 1.6 mmol/L or 30 mg/dL after you eat), delaying your meals until your blood sugars are lower using Data-Driven Fasting may be more helpful.

If your blood sugars are elevated in the morning, then there’s a good chance you are above your Personal Fat Threshold and need to lose some body fat.  Once your blood sugars after meals start to stabilise, you should focus on high satiety, nutrient-dense foods and meals to help you continue to reduce your body fat, which will, in turn, reduce your fasting blood sugar levels.  

What should I eat?

To help with this, we have created a series of 22 nutrient-dense recipe books that will help you maximise satiety and provide you with all the nutrients you need while you are losing weight.  

As your adipose tissue becomes less full, it will be able to do its job of storing the extra energy properly when you eat rather than allowing energy to overflow into the bloodstream and your vital organs.  

Focusing on a diet with less processed carbohydrates and more high satiety nutrient-dense foods and meals will have far-reaching health impacts.   

Keep it simple!

Testing your blood sugars regularly will give you a little more clarity on your risk.  But the best measurement of your risk is a simple tape measure.  

Rather than stressing about the minutia and endless debate about cholesterol, you should do what it takes to lose fat until your waking blood sugars stabilise and your waist to height ratio comes down to below 0.5.  Once you get that right, most other things will fall into place.  


Special thanks to Paul Mason, Dave Feldman, RD Dikeman, Helen Kendall, Caroline Elizabeth and Michelle McGuinness for their review and feedback on this article.