Person about to eat dinner while wondering about the reasons for high cholesterol other than diet

Here’s Why Diet Isn’t The Only Possible Reason For High Cholesterol

Updated December 12, 2023. Medically reviewed by Rosanna Sutherby, PharmD. Written by Caitlin Boyd. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.

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“Why is my cholesterol high?” If you find yourself asking that, you aren’t alone. High cholesterol, a well-known risk factor for heart disease and stroke, affects about 2 in every 5 American adults. [1] That’s arguably a pretty large proportion of adults who have high cholesterol – and it raises the question: why is high blood cholesterol so common?

Diet and High Cholesterol

Dietary habits, as many people know, are often responsible for high levels of cholesterol: eat a lot of foods high in saturated fat – cheeseburgers, for instance – and your blood cholesterol level might swing upwards. [2] (We know, they’re delicious.)

While a diet high in saturated and trans fat can increase your total cholesterol level and cause high LDL and triglyceride numbers, this isn’t always the whole picture when it comes to cholesterol levels: high blood cholesterol can make an unwelcome appearance even if you’re very careful about eating a healthy, balanced diet.

Here’s why: there are other potential drivers of high cholesterol, such as a lack of exercise and one’s genetics. (So it can be helpful to check your blood cholesterol levels regardless of your dietary habits – something you can now do from the convenience of home with our home cholesterol test. You can also check up on indicators of your heart health at home with our Heart Health Test.)

So read on to take a closer look at both of these non-dietary reasons for high cholesterol if you’re wondering “Why is my cholesterol high when I eat healthy foods?”

Exercise and Cholesterol

Truth be told, it’s not always easy to find the time – or the motivation – to consistently exercise. But take note: regular physical activity is an absolute must if you want to safeguard your body’s health and well-being. Exercise, after all, has many benefits – both physiological and psychological (“there is irrefutable evidence,” wrote one group of researchers, that regular physical activity can help prevent many chronic diseases and premature death [3]). Incorporating exercise or workouts into one's schedule and eating a balanced diet are both lifestyle changes that are often recommended for people who want to maintain a healthy weight and lower LDL.

On the flip side, a lack of exercise frequently comes with a variety of health consequences – some of them rather severe. One health consequence, for example, is an increased risk of gaining an unhealthy amount of weight.

Over the long term, a lack of exercise can lead to obesity – which, in turn, can significantly lift cholesterol levels. In fact, up to 70% of patients with obesity have abnormalities in their cholesterol and triglyceride levels. [4] Importantly, when obesity causes a high cholesterol level in the body, it’s – more often than not – the levels of “bad cholesterol” (LDL cholesterol) that tick upward. But levels of “good cholesterol” – or HDL cholesterol – on the other hand, are often low. (If you have a high triglyceride level and/or LDL level, it’s a good idea to talk with your healthcare provider to learn what steps to take next. Possible therapies may be medication, including more omega-3-rich foods that lower triglycerides in your diet, and more.)

And there’s more: obesity can elevate the amount of small dense LDL particles in the bloodstream. These LDL particles – very small in size, as their name suggests – can easily slip into the walls of your arteries (the vessels that carry blood from the heart to the rest of the body), prompting a plaque buildup. The arteries affected by plaque buildup frequently harden and narrow as a result, significantly slowing blood flow – a condition known as atherosclerosis. Alarmingly, the risk of suffering from a stroke or heart attack shoots up when your arteries are in this condition.

With all this in mind, then, if you are overweight or obese it’s important to routinely check your cholesterol levels. If your cholesterol levels are in fact too high, consult with a health care provider on the next steps to take that’d be best for you. Regulating cholesterol levels in your body may help improve your heart health and overall well-being.

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Genetics and Cholesterol

Has someone in your family had a heart attack even though they were fairly young? If your answer is “Yes,” you could be at a risk for “familial hypercholesterolemia” – an inherited, genetic lipid disorder that’s characterized by high blood cholesterol levels at a young age and a higher-than-normal risk of heart disease. [5]

In women, for example, untreated familial hypercholesterolemia leads to a 30% risk of a coronary event (such as a heart attack) by age 60. That risk climbs to 50% in men by age 50. [6]

What's more, this genetic condition can cause elevated cholesterol even if someone eats a well-balanced diet and gets regular physical activity—something to keep in mind if you’ve wanted to find out more about the causes of high cholesterol in a “healthy” person.

So what is it exactly about this genetic lipid disorder that causes cholesterol levels to reach disturbingly high levels? To answer that, we need to talk about something called “LDL receptors.” LDL receptors are special devices on the surface of many of your body’s cells. Their job description is straightforward: to catch particles of LDL cholesterol flowing in the bloodstream and take them inside the cell (where the LDL cholesterol is broken down). [7]

In this way, LDL receptors continually clear your LDL cholesterol from the bloodstream – so there’s much less LDL cholesterol around to gum up the arteries with plaque.

But if you have familial hypercholesterolemia, your cells don’t have very many of these receptors – so particles of LDL cholesterol build up in your bloodstream faster than they can be cleared away. [7]

Symptoms of Hypercholesterolemia

There are often no symptoms of hypercholesterolemia in most people. [8] However, severe cases of the disease may lead to cholesterol deposits on the eyelid skin or connective tissue. A cholesterol level that’s much higher than average for your age is another clue. [8] If you’re concerned about familial hypercholesterolemia, you should consult with a healthcare provider. Only a qualified healthcare professional can make an accurate diagnosis.

Measure Cholesterol and Lipids With Everywell

High cholesterol can lead to heart disease, stroke, and other health problems. [1-2] Many of us associate high cholesterol with a poor diet, but the truth is that other factors can also impact cholesterol levels. [1-3] Fortunately, you can check your cholesterol and lipid levels at home with a cholesterol test collection kit. You can even test regularly by signing up for Everlywell+, an at-home lab testing membership. For just $39/month, gain access to all of Everlywell’s at-home lab tests. Measure a variety of metrics, or keep tabs on a specific area of your health. Learn more about Everlywell membership options.

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1. Cholesterol. Centers for Disease Control and Prevention. Updated September 2023.

2. Saturated Fat. American Heart Association. Reviewed November 2021.

3. Ruegsegger GN, Booth FW. Health Benefits of Exercise. Cold Spring Harb Perspect Med. 2018;8(7):a029694. Published 2018 Jul 2. doi:10.1101/cshperspect.a029694

4. Feingold KR, Grunfeld C. Obesity and Dyslipidemia. In: Feingold KR, Anawalt B, Boyce A, et al., editors. Endotext [Internet]. South Dartmouth (MA):, Inc.; 2000. Updated June 2023. Available from:

5. Knowing Your Risk for High Cholesterol. Centers for Disease Control and Prevention. Updated May 2023.

6. Knowles JW, O'Brien EC, Greendale K, et al. Reducing the burden of disease and death from familial hypercholesterolemia: a call to action. Am Heart J. 2014;168(6):807-811. doi:10.1016/j.ahj.2014.09.001. Accessed Dec 14, 2023.

7. LDLR gene. Genetics Home Reference. Updated January 2020. Accessed December 2023.

8. Hypercholesterolemia. Cleveland Clinic. August 2022. Accessed December 2023.

Originally published on February 6, 2019.

Rosanna Sutherby, PharmD holds a PharmD and is a retail pharmacist who has worked in the industry for roughly 20 years. Sutherby has extensive knowledge about medications, diseases, and conditions, and knows how to confidentially educate patients. Sutherby also creates content revolving around anything in the medical sphere with a focus on conditions and articles. Her published work spans a variety of topics, including cardiovascular health, immunology, sleep disorders, mental health, alcohol and opioid use disorders, vaccine education, and medication use and safety.

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