Ketosis and Cancer: What You Really Need to Know

For some, it sounds extreme.
For others, it feels like the “only” option.
And for many, it feels confusing and overwhelming.

Let’s slow this down and bring clarity because in the world of cancer support, fear-based nutrition helps no one.

Ketosis Is a Metabolic State—Not a Specific Diet

This is the first thing most people don’t realize:

Ketosis is not a diet.
It’s a metabolic state.

Ketosis simply means your body is producing and using ketones for fuel because glucose availability is lower. Remember from last week's blog that 70-80% of cancers use glucose as their fuel source.  They are not metabolically flexible to use ketones.   

A state of ketosis can be achieved in different ways, including:

• Lower-carbohydrate eating

• Therapeutic ketogenic nutrition

• Periods of fasting 

• Increased metabolic flexibility over time

A ketogenic diet is one structured way to encourage ketosis, but it’s not the only path.

And it doesn’t have to look like extreme carb elimination, packaged “keto” products, or rigid food rules.

What Happens in Ketosis

When the body shifts from relying mostly on glucose to using fat and ketones for fuel, it often leads to:

• Lower and more stable blood sugar

• Reduced insulin signaling

• Increased metabolic flexibility in healthy cells

Metabolic flexibility simply means your healthy cells can adapt to different fuel sources when needed.

This flexibility is one of the reasons ketosis is talked about in metabolic health conversations.

Why Ketosis Is Discussed in Cancer Care

Early metabolic research from scientists like Otto Warburg observed that many cancer cells rely heavily on glucose metabolism. More recent researchers such as Thomas Seyfried have expanded on this metabolic perspective.

Because many cancer cells are less efficient at using ketones compared to healthy cells, strategies that lower glucose and insulin signaling can be used as metabolic support alongside conventional treatment.

A therapeutic ketogenic approach may:

• Reduce circulating glucose

• Lower insulin and certain inflammatory signals

• Support healthy cells that can adapt to ketones

Ketosis is about shaping and healing the terrain, not attacking the body.

What It Does Not Do

Let’s be very clear:

• Ketosis does not cure cancer

• Keto does not replace treatment

• Strict carb restriction is not required for everyone

• You do not have to be in deep ketosis to support metabolic health

And perhaps most importantly:

If a strategy creates overwhelm, anxiety, or rigidity, that stress matters too.

Your nervous system is part of your terrain.

One Size Does Not Fit All

Some women thrive with deeper carbohydrate restriction and measurable ketosis.

Others do better with:

• Moderate carbohydrate reduction

• Blood sugar stabilization without chasing ketone numbers

• Strategic fasting where appropriate

• A phased approach 

Factors that matter include:

• Treatment status

• Stress levels

• Hormonal shifts

• Sleep quality

• Activity level

• Emotional capacity

• Digestive resilience

The goal is not ketosis at all costs.

The goal is metabolic stability and resilience.

Permission to Breathe

You do not need to overhaul everything overnight.

Ketosis is a tool.
Nutrition is a tool.

You are allowed to move slowly.
You are allowed to personalize.
You are allowed to choose what feels sustainable.

Next week, we’ll bring this into real life and talk about gentle, practical ways to support your metabolism without perfection, without extreme rules, and without losing yourself in the process. 🌿