Dr Karen L Hartzenberg

25/02/2026

Get the benefits of exercise in 2-3 minutes at work

22/02/2026

Want to break the carb craving cycle? Watch the video to get a great tip!

Subscribe and learn how to improve your overall vitality and well being, and take control of your health. Adopt an approach that is sustainable, learning and making small changes at your own pace to achieve your goals. Relatable and easy to understand, these newsletters will encourage you and gently guide you towards a healthier, happier you: http://eepurl.com/ih2PMP

14/02/2026

Autophagy is a powerful tool you can harness through fasting and exercise. Benefits include: Lower inflammation, anti-ageing / rejuvenation, and anti-cancer effects.

Did you know that our body 'eats' itself in order to stay healthy?

Autophagy, or 'self-eating' refers to the way our cells can destroy their contents, by breaking them down and recycling them in a compartment called the lysosome. In the 1990s, Yoshinori Ohsumi discovered how autophagy worked. His discoveries helped us better understand how our cells manage malnutrition and infections, and protect us against disease.

Ohsumi was awarded the 2016 Nobel Prize in Physiology or Medicine.

Learn more: https://bit.ly/2yw7ztz

12/02/2026

Feeling the weight of stress?

Stress is not just psychological – it can actually change your body.

Meet Ms. L – a single mom and busy teacher. She was under constant stress: her son recovering from surgery, her father diagnosed with cancer, and a toxic work environment. Despite running regularly and eating well, she gained 8kg in 6 weeks.
As she grabbed a fat roll on her belly, she exclaimed: “I look 7 months pregnant!”
Her blood tests revealed high cortisol levels and insulin resistance – classic signs of chronic stress.

Important lesson: Stress doesn’t just mess with your mind – it messes with your metabolism, too.

Here’s the good news: stress can be managed! And, the effects of high cortisol can be reversed.

In just 6 weeks, with some simple changes, Ms. L lost 4kg, felt more energized, and had a smaller waistline.

Here’s what you can do if stress is impacting on your physical health:
✅ Exercise regularly – even short bursts of activity work wonders!
✅ Prioritize sleep – stress recovery starts with rest.
✅ Practice mindfulness – calm the body, calm the mind.
✅ Focus on a whole-food, low-carb diet to balance hormones.
You can manage stress and reclaim your health!

To read the full story of Ms. L, click here: http://lifestyledoc.co.za/the-case-of-stress-bod-a-real-life-example/

09/02/2026

Working on resisting a hunger impulse? Watch the video to get a great tip!

Subscribe and learn how to improve your overall vitality and well being, and take control of your health. Adopt an approach that is sustainable, learning and making small changes at your own pace to achieve your goals. Relatable and easy to understand, these newsletters will encourage you and gently guide you towards a healthier, happier you: http://eepurl.com/ih2PMP

04/02/2026

Amen!

Is Failing to Prescribe Lifestyle Medicine Malpractice?

Modern medicine is extraordinary. We can administer all sorts of drugs and procedures. We can reattach a severed finger. We can open up your skull and remove a brain tumor. We can scan and detect complex pathologies deep inside the body. And so much more.

Yet every day, we make a quiet ethical mistake.

We treat early-stage chronic disease as if the only serious options are pharmaceutical. We might mumble “try lifestyle” or “lose some weight” at the end of the consultation, but we do not prescribe it. We do not explain it. We do not support it. We do not frame it as a real first-line, and usually most effective, treatment.
When we fail to offer a clear, practical explanation of lifestyle treatment options, including the likely benefits compared to the real risks of medication then we are not practising ethically. We are practising conveniently.

The moment we choose a path

John, 46, gets his blood test results back. His HbA1c is climbing into the diabetes range. Blood pressure is elevated. Liver enzymes hint at fatty liver. His waist has crept up. Sleep is not great. His mood is low.

John is not “sick” in the way most people imagine sickness. John is in the middle of a long metabolic slide. This ends in an early death with an extra decade or two of disability.

This is the moment where we have the most leverage. Metabolic disease, as yet without complications, is highly responsive to lifestyle treatment. But what typically happens?

John gets a statin, an anti-hypertensive, metformin, and a pamphlet. The lifestyle conversation is reduced to a vague moral instruction: eat better, move more, lose weight. He might also be offered an anti-depressant.

No plan. No options. No follow-up. No realistic support. No explanation about side effects, what behaviour change means in terms of results, or how to get there.

That is abandonment with good intentions.

Lifestyle is not an add-on. It is the treatment.
I need to be clear: structured lifestyle change is not a soft suggestion. It has decades of clinical trial evidence behind it, with effects that often exceed medication.

The notion of the “reversal” of chronic disease is only possible with this type of treatment.

But it is hard. It requires knowledge, support, and intensity from the medical system. It requires deep knowledge and expert practice in metabolic and behavioural medicine. Neither is well taught in medical schools or to other health professionals.
This is not fringe. It is evidence-based care. The real question is: why is it still treated as optional in practice?

The 4 Pillars of Medical Ethics and the Problem of Omission
If you accept that lifestyle intervention is a genuine and effective treatment option, then failing to offer it properly becomes an ethical issue, not merely a style issue.

Let’s apply the pillars.

1. Beneficence Act in the patient’s best interest.
In early-stage chronic disease, the "best interest" is not only short-term biomarker improvement. It is also long-term function, independence, and reduced treatment burden.

Lifestyle treatment can do something medication often cannot: it can move the patient onto a different trajectory. It can reduce the need for medication, sometimes dramatically, and in some cases can achieve remission in type 2 diabetes.

When clinicians default to medication without giving lifestyle treatment a serious, structured offer, we are not maximising benefit. We are choosing the path that fits the appointment length, not the path that offers the greatest future. Beneficence is not satisfied by “I mentioned diet at the end” or “I told them to lose weight.”

2. Non-maleficence Do no harm.
There are harms of commission, and there are harms of omission. Harm of commission is obvious: side effects, drug interactions, and the slow creep of polypharmacy. Harm of omission is subtler but just as real: missed reversal opportunities, progressive disease, and the psychological message that decline is inevitable.

If someone could have meaningfully improved, or even reversed, early-stage metabolic disease with structured lifestyle treatment, but was never offered that option in a practical way, then the system has facilitated harm.

3. Autonomy Respect informed consent.
Autonomy is not a signature on a form, or a simple “yes.” It is a patient actually understanding their options.
Here is the uncomfortable truth: if you do not clearly explain lifestyle as a treatment option, including realistic effort, support requirements, benefits, and limits then the patient cannot choose it.

Informed consent could sound more like this:
"Here is what your condition means and where it is likely heading if nothing changes."

"Here are your treatment options: medication, lifestyle treatment, or a combination."
"Here is what lifestyle treatment can achieve in many people when done properly, and here is what it requires."
"Here are the risks and the safety issues, including for the medications."
"What matters most to you, and what support do you need to pursue the option you want?"

If we skip that, we are not respecting autonomy. We are steering the decision by omission.

4. Justice Fairness and equity.
Right now, lifestyle support is often a luxury item. People with money can buy coaching, dietetic care, personal training, meal support, and time. People without money get a prescription and generic advice.

That is not justice.

A medication-only model widens inequality because it treats symptoms while leaving upstream drivers untouched, and because it shifts responsibility onto individuals without providing the tools that make change feasible.

Justice means structured lifestyle treatment must be accessible, not aspirational. The ethical obligation is not just on individual clinicians; it is on health systems to fund the support that makes first-line lifestyle treatment real.

When does poor ethics become negligence?

This brings us to a harder question. At what point does the failure to discuss lifestyle move from "unethical" to "negligent"?
Historically, doctors were protected by the "Bolam test", essentially, if a body of medical peers agreed with your approach, you weren't negligent. Since most doctors ignored lifestyle, ignoring lifestyle was considered the standard of care.

But the legal ground has shifted.

Courts in the UK (the Montgomery ruling) and elsewhere have moved toward a standard of Material Risk. The law increasingly states that a doctor has a duty to take reasonable care to ensure the patient is aware of any reasonable alternative or variant treatments.

The test is no longer "Would other doctors do this?" The test is "Would a reasonable patient want to know this?"

Ask yourself: Would a reasonable patient, diagnosed with a progressive condition like Type 2 Diabetes, want to know that there is a treatment option (lifestyle intervention) that could potentially reverse the disease and remove the need for lifelong medication?

The answer is obviously yes.

Therefore, failing to disclose lifestyle change as a valid, evidence-based alternative, or at least powerful adjunct, to medication is increasingly likely to be viewed as a breach of duty. If a patient suffers harm from medication side effects, or from the progression of a disease they could have reversed, and they can prove they were never told reversal was an option then that is the definition of negligence.

We are entering an era where "I didn't think they would stick to the diet" is no longer a valid legal defence for failing to prescribe it.

The Bottom Line
You are either on the receiving end of the medical system, so push back and demand more ethical engagement. Or you are the one seeing patients, so ask yourself: how ethical is your practice?

OK, I get it. The system isn't set up for this. You are busy. You have 15-minute appointments. There is no funding for lifestyle interventions. These are all real constraints.

But at the end of the day, why did you become a health professional? The answer is usually “to help people be healthy” and “to give the best possible care.”

Are you?

02/02/2026

🍎 Is fruit really healthy... or is it just sugar in disguise?
“Dr Karen, should I stop eating fruit if I’m watching my sugar? Should I cut out fruit if I want to lose weight?”

No, you don’t need to fear fruit — but you do need to understand it.

Modern fruit is very different from what our ancestors once picked. It’s been bred to be bigger, juicier, and much sweeter… which means we have to be more mindful of how we eat it.
Here’s the truth:
🍊 The sugar in fruit (fructose) is naturally “buffered” by fibre and water, which slow absorption and protect your metabolism.
🥝 The problem isn’t the fruit — it’s the juice, smoothies, and dried versions that deliver sugar without fibre.
💡 My top tips:
✔️ Eat fruit whole, not juiced or blended.
✔️ Pair it with protein or healthy fat (like nuts or yoghurt).
✔️ Enjoy it as dessert, not as a mid-morning sugar hit.
Fruit isn’t the enemy… it’s a friend — when eaten the way nature intended.
🍓 Save this as a reminder next time you reach for a “healthy” smoothie.
To read more about ways to enjoy fruit without any of the downsides, visit:

31/01/2026

When the ward breaks you… and movement puts you back together

Life as a junior doctor in Africa can be brutal: long shifts, broken sleep, weekends on call, and stress so high you can taste it.

One colleague of mine didn’t just struggle — she unravelled.

It started like it often does: more coffee, more sugar, more “quick fixes”. Then the drinking escalated. She withdrew. Lost weight. Became unreliable. And then came the part that still makes my stomach tighten: major clinical mistakes.

It escalated to a disciplinary hearing, mandatory sick leave… and months away from work.

When she returned, she was a different person — grounded, cheerful, present, functional.

I assumed antidepressants. Therapy. A psychiatrist.

Instead she said:
“Medication wasn’t my long-term answer. I had to change what I was physically doing to cope.”

Her treatment was exercise.

She joined a gym and threw herself into movement: step class, spinning, kickboxing, dance, aerobics. Within weeks, her mood shifted. Back at work, the stress was the same, but now she had a way to evacuate it — safely, powerfully, consistently.

So what’s going on inside the brain?
Exercise boosts and balances key systems that affect mood and resilience, including:
✅ Dopamine, serotonin & noradrenaline (motivation, mood, focus)
✅ Endorphins + endocannabinoids (calm, relief, “I can breathe again”)
✅ BDNF (brain plasticity + resilience)
✅ Stress regulation + cortisol balance
✅ Inflammation reduction + better sleep
And no — not all movement is equal. Walking, strength training, yoga, and HIIT affect the nervous system differently (and choosing the right one matters if you’re anxious, depressed, burnt out, or not sleeping).
If life feels heavy right now, start here:
10 minutes counts. Walking counts. “I did it anyway” counts the most.
👉 I explain the exact mechanisms and give an easy “exercise prescription” for depression, anxiety, and insomnia in the full post
https://lifestyledoc.co.za/when-the-ward-breaks-you-and-movement-puts-you-back-together/

(Important: if you feel unsafe, suicidal, or unable to function, please seek urgent professional support — exercise is powerful, but not the only tool.)

29/01/2026

Here’s a question for you…
If you sat on the floor right now…

Could you get up without using your hands?

Today at the beach, I watched a woman struggle to stand up from the sand. Her husband had to lift her… and it reminded me how mobility shapes our future.

This isn’t about “being fit”…
It’s about independence.

Mobility check: If you are sitting on the floor, could you get up…
A) Easily… with no hands
B) Using one hand
C) Using both hands
D) With the help of furniture or someone else?

Whatever your answer, this isn’t judgment… it’s information.

Your ability to rise from the ground reflects strength, balance, flexibility, and real-world resilience… and research suggests it may even be linked to longevity.

I’ve written a blog explaining what this means (and how to start improving your mobility safely, even if you’re starting from zero).

👉 Read the full blog here: https://lifestyledoc.co.za/can-you-get-up-from-the-floor-this-question-matters-more-than-you-think/

27/01/2026

“Dr Karen, I’d love to eat healthy… but it’s too expensive.”

I hear this all the time.

And yes… a basket full of fresh vegetables, fruit, whole grains and good quality protein can cost more than a trolley full of ultra-processed food.

But here’s what we rarely talk about:
The cost of not eating well.

In my own life, years of fast food, sugary drinks and sweets every day gave me:
⚠️ Low energy
⚠️ Low mood
⚠️ PCOS
⚠️ Horrible periods
⚠️ Obesity
⚠️ High blood pressure
I ended up in hospital.

A week in a hospital bed… scans… blood tests… specialist fees…
That is not cheap.

And in my practice I’ve seen even more devastating examples:
▫️ A 32-year-old mum with type 2 diabetes and a stroke, now paralysed on one side and unable to work
▫️ A 48-year-old marketing executive on dialysis three times a week after years of a salty, processed diet
▫️ A 55-year-old woman who loved canned spaghetti and bully beef… who came in vomiting blood and was found to have stomach cancer
These are extreme cases… but they are real.

Healthy eating is not a guarantee.

But it is one of the strongest insurance policies you can give your body.
You will pay for your food one way or another.

Either you invest more in real, nourishing food now… or you pay later in medication, hospital time and lost quality of life.

Visit my full blog on this with real stories and practical tips for eating well on a budget: https://lifestyledoc.co.za/is-healthy-eating-really-too-expensive-the-hidden-cost-of-a-poor-diet/

20/01/2026

Make the healthy choice the obvious choice!

Adjust your environment to make it easier for you to change your habits!

Learn more and pick up easy tips in this video

16/01/2026

They told us fat was BAD.
So the food industry removed fat… and added sugar.

And we’ve been paying for it ever since:
More cravings, more snacking, more “low-fat” ultra-processed foods… and worsening metabolic health.

Now the new nutrition guidelines released this month have finally acknowledged what real experts and scientists have been saying for decades:
✅ Stop living on ultra-processed food
✅ Prioritise protein
✅ Cut added sugar (and sugary drinks)
✅ Choose real-food fats (hello olive oil, butter, cream, eggs and good-quality cheese👋). No need to cut the fat off your steak or remove the skin from your chicken anymore!
✅ Refined carbs are the real problem

If you’ve been trying to “eat healthy” but still feel hungry, tired, and stuck… it might not be your willpower.

It might be the food environment.
I unpack the history, the flawed science, what changed in the new guidelines, and how you can practically apply the recommendations in your life.

👉 Read the full breakdown on my blog: https://lifestyledoc.co.za/the-food-pyramid-just-got-flipped-what-the-new-nutrition-guidelines-mean-for-you/