Helping patients adopt low carb

How do you decide which of your patients will benefit most from adopting a low-carb or keto diet? How do you introduce it in a supportive and respectful way? This guide helps answer those questions.

It consists of the following sections:


1. Who might benefit from low carb


We all know how challenging it is getting patients — or anyone — to change behaviors. Decades of trying to get patients to reduce their calories, lower their fat intake, and exercise more has jaded many physicians against therapeutic lifestyle interventions.

However, for many low-carb doctors lifestyle has become the most rewarding part of their medical practice. What used to be frustrating and demoralizing — chronically ill patients who only got worse — is now inspiring and joyful.

Instead of increasing doses and adding more medications, low-carb doctors are reducing drug dosages or removing them entirely. Patients who adopt the changes come into appointments excited and empowered.

As UK physician GP Dr. David Unwin notes: "They are now my absolutely favorite patients. I am having cheerful conversations with previously unhappy people. Using ‘lifestyle medicine instead of lifelong medication’ can help patients really take control of their health, leading to greater doctor and patient resilience."1

Who can benefit: Strong scientific evidence

The most common chronic conditions, for which strong scientific evidence exists to support low-carb dietary treatment, include the following:

Who else might benefit: Anecdotal or preliminary evidence

Many people report significant improvements with other health conditions using low-carb or keto diet, but currently evidence is anecdotal or preliminary. It is not known whether reported improvements may be due to weight loss, hormonal factors, or other effects of ketones. It may be worth saying to patients, however, "This might help, would you like to try?"

These conditions include:

Although we are unaware of any high-quality published studies, some healthier patients could potentially benefit from a low-carb diet for disease prevention. These include those who:

  • Have family histories or strong risk factors for chronic diseases such as type 2 diabetes, cardiovascular disease or metabolic syndrome.
  • Have a strong interest in adopting healthy habits or improving athletic performance.
  • Are the spouse or partner of a patient or the parent of a child who might benefit from low carb.

When to suggest low carb

The ideal time to talk with patients about trying low carb or keto is when they are in your exam room sharing a concerning symptom or following up on a medical test. Typical examples include:

  • New lab results such as a recent blood test that shows a new diagnosis of type 2 diabetes or pre-diabetes, elevated liver enzymes suggesting NAFLD, high inflammatory markers, elevated androgens of PCOS, etc.
  • Weight gain since their last appointment, despite efforts to lose weight using other unsuccessful methods, such as calorie restriction and exercise.
  • Higher blood pressure despite attempts at lifestyle modifications or the use of medications;
  • Increase in medications for any of the conditions that can respond to low carb, whether it is increasing doses or adding a new medication like insulin.
  • A non-healing wound, such as a foot or leg ulcer from diabetes, especially those that require or have not responded to antibiotics.
  • Troubling symptoms such as joint pain from excess weight or inflammatory conditions; irritable bowel syndrome; amenorrhea, weight gain or hirsutism from PCOS. Even some of the conditions for which there is preliminary evidence —acne, sleep apnea, migraines, heart burn, mental health conditions —patients may be very eager to try using low carb.
  • Concern over the cost of medications.
  • Supporting a loved one with health issues in which their participation may greatly contribute to health improvements.


2. How to talk about low carb with patients

How to have the conversation

As we mentioned previously, many patients struggle with behavior change. Plus, given doctors’ limited time to spend with patients, sometimes it feels like the best we can do is say "Take this medication", "Stop smoking", "Reduce your alcohol," and now with low carb: "Cut out sugar, starches and refined carbohydrates and up your healthy fats."

While we can’t magically give you more time in your patient visit, here are some suggestions about how to make your lifestyle suggestions more impactful.

Collaboratively motivating for change

Mounting evidence suggests that most patients are more motivated to take control of their health with a collaborative coaching approach.

This approach treats them as equal partners, giving them the confidence to make the changes needed to improve their health.

"If we threaten patients, “Do this or else“; many close down and maybe not come back for five years. If we give them hope, by starting to talk about a better life, it can be so much more motivating. For example try inviting them to think about a health goal that matters to them personally. For you, as a doctor, it may be to get their HbA1C down, but perhaps they don't care so much about that. Their goal may be to be able to play with their kids, breath better or lose weight. Then a great next question could be ‘what difference would losing weight make to your life?' This question helps the patient think more realistically about a preferred future. Only then do you work with them to help decide the steps they can take to achieve their goal" says Dr. Unwin.

This style of collaborative interaction has many different names, such as life-style coaching, behavioral counseling, and motivational interviewing. More than 3600 published journal articles, videos and organizations demonstrate and evaluate the effectiveness of motivational interviewing and give specific tips and techniques.

The support of this approach to patient engagement is strong, even if they have mostly been used to promote the less-than-helpful "calories in- calories out (CICO) " model of "eat low fat" "eat less, move more". Engaging patients with low carb information in this empowering style has the potential to achieve even better, lasting results.

For more information on key principles of effective doctor-patient interactions, you can learn more here:

Key principles of effective doctor-patient interactions

Whatever the approach you use, some universal principles exist for positive engagement with patients to motivate behavior change:

  • Collaborative partnership: you and the patient identify shared goals and work together to identify the realistic steps he or she can take to achieve those goals.
  • Empathy: you recognize and are compassionate towards the patient's struggles and previous experiences and are non-judgmental about any actions and choices.
  • Respect: you recognize and support patients' autonomy and other positive characteristics and resources they bring to their own issues. You do not shame or lecture them.
  • Patient permission: you ask patients' permission to proceed in discussing certain areas. These are question like "Would you like to hear more about a few changes you might make…?"; "Do you want to hear about other options….?"; "Can I talk to you about some lifestyle changes that might help…?"
  • Simple information: you don't overwhelm patients with scientific details and complex explanations. Having a pamphlet ready with key points and referring them to a reliable site like Diet Doctor can enable you to keep the information short in the exam room. You can then focus on key concepts and actions they can take. (See the next section.)
  • Open-ended questions: once permission to proceed is given, the questions you ask should encourage patients to talk about how they feel, what they want, what they can do, and not elicit simply a yes or no answer. Get them talking with questions like: "How does that make you feel…?" "What do you think about that?"
  • Affirming abilities: give statements and gestures that recognizes patients' strengths and acknowledges positive behaviors, no matter how big or small. Affirmations build confidence in patients' ability to change. "That is a great suggestion….." "You did really well with that…." The affirmations are even more important when the patient comes back to see you in a few weeks. "You have made great progress….".
  • Reflective listening: hearing what patients tell you and then paraphrasing it back to them shows you are listening. Such attention can move them in a positive direction. "I hear you saying that …","What you just told me is ……"
  • Summarizing next steps: Summing up what you talked about in the appointment can provide the patient with a concrete and clear list of actions he or she can tackle. Summations also clarify anything not understood and provide transition and closure to the appointment. "So we’ve decided that to help you get your diabetes under control, you are going to go home and….." As you list of the actions the patient and you have agreed to you can ask. "Is that right? Do you have any questions?"

Talking about obesity with a patient

Most doctors find it much easier to talk about type 2 diabetes and other clinical diagnoses with a patient than to initiate a discussion about a patient's excess weight.

"It can feel rude or impolite to talk about their obesity, so doctors may avoid even bringing it up, " says Dr. Unwin.

The respectful approach that Dr. Unwin uses to bring up weight issues is to first listen to patients and their symptoms.

Hear how they are telling you about sore knees or feet, their fatigue, their difficulty catching their breath climbing the stairs and other symptoms that may be related to their obesity.

After you have heard their symptoms, ask permission to talk about their weight. "Do you think your weight may have something to do with your sore feet?" If you get even a head nod, then ask, "Would it be all right if we talked more about that? I have some ideas that might help…."

Once you have permission to talk about their weight, you can then use the various principles outlined above to go into a more collaborative, patient-focused discussion about their goals for weight loss, what methods they may have tried before, how low carb principles might help them, and then define with some tangible low carb steps that they might be motivated to take.


3. Reducing carbohydrates step by step

Making the low carb information simple: relating it to sugar cubes

We know most doctors have limited time with their patients, and likely won’t have the chance to discuss the physiology of fasting blood glucose, insulin response, gluconeogenesis, the misguided war on fat and more. That is where we come in. We hope to be your reliable and trustworthy source to provide all the in depth knowledge that your patents desire.

We also want to give you advice how to address carbohydrate restriction in a time efficient and effective manner. We recommend using the glycemic load as equivalents of teaspoons or cubes of sugar. This can be a powerful, memorable and actionable explanation for a patient in a very short time.

Most patients understand that sugar is not good for them. Many, however, do not understand how carbohydrates break down in the body into glucose with a surprising equivalent of teaspoons or cubes of sugar.

Some low-carb doctors keep a big jar of sugar cubes in the exam room and ask patients to estimate how many cubes are in their morning cereal, bagel, and glass of juice. A simple act of physically adding a number of cubes to their underestimates can drive home the message that carbs, as they break down with digestion, act like sugar in their bodies.

Dr. Unwin and other low-carb doctors in the UK have created powerful visual aids, available through the Public Health Collaboration, that shows how common carbohydrate foods break down into teaspoons of sugar. These guides are available for doctors to download and use in the office. One look at the infographics and the patient usually quickly gets the concept. Please find below an example.

The effect of foods on blood glucose
Food item G index Serve size g Effect on blood glucose compared with one 4 g teaspoon of table sugar
Basmati rice 69 150 10.1 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100
Potato, white, boiled 96 150 9.1 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100  
French fries, baked 64 150 7.5 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100 0.5_spoon_sugar_100    
Spaghetti, white, boiled 39 180 6.6 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100 0.5_spoon_sugar_100      
Sweet corn, boiled 60 80 4.0 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100            
Frozen peas, boiled 51 80 1.3 spoon_sugar_100 0.25_spoon_sugar_100                
Banana 62 120 5.7 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100 0.5_spoon_sugar_100        
Apple 39 120 2.3 spoon_sugar_100 spoon_sugar_100 0.25_spoon_sugar_100              
Wholemeal, small slice 74 30 3.0 spoon_sugar_100 spoon_sugar_100 spoon_sugar_100              
Broccoli 54 80 0.2 0.25_spoon_sugar_100                  
Eggs 0 60 0                    


It comes from The Journal of Insulin Resistance “It’s the glycemic response to, not the carbohydrate content of food that matters in diabetes and obesity: The glycemic index revisited.” D J Unwin et al. It shows the glycemic load reinterpreted as 4g teaspoons of sugar:

  • A bowl of basmati rice equals 10.1 teaspoons of sugar
  • A white potato, boiled, is 9.1 teaspoons of sugar
  • A bowl of spaghetti is 6.6 teaspoons of sugar
  • A banana is 5.7 teaspoons of sugar
  • A piece of brown toast is 3 teaspoons of sugar
  • A floret of broccoli is just 0.2 teaspoons of sugar
  • One egg is zero teaspoons of sugar.

By quickly estimating, with the visual guide or with a jar of sugar cubes, how much sugar they are consuming from carbohydrates, you can dramatically demonstrate the impact carbs are having on their blood sugar and show how easy it may be for them to reduce their sugar load.

For example by showing them that their daily breakfast of juice, cereal, milk and a piece of toast has 21 teaspoons or cubes of sugar, you can then show them how bacon and eggs with black coffee has zero. Easy change.

Empowering them with substitutions

Some patients will immediately understand the sugar comparison but may be confused about what to eat instead. Ask them what they typically eat in a day, and give them an easy substitution.

  • If breakfast is usually cereal, juice, and toast suggest eggs, bacon, and coffee (with heavy cream, if wanted) instead.
  • If lunch is a sandwich with deli meat, how about salad with sliced chicken or steak and plenty of extra virgin olive oil as the dressing instead?
  • If dinner is often a meat with a starch like pasta, potatoes, or rice, tell them to have as much meat as they like, fill the rest of the plate with green vegetables or salad. They can even try adding cauliflower rice, zucchini noodles, or other starch substitutions.
  • If between meal snacks or after meal desserts are stumbling blocks, recommend eliminating the soft drinks, junk food and sugary desserts but feel free to drink sugarless tea, coffee or water and snack on nuts and cheese. For dessert have berries and unsweetened whipping cream or full fat yogurt.

How low to go?

Not every patient needs to adhere to a strict low-carb diet to achieve their desired results. Generally, however, the lower the carb intake the more powerful the results. People with type 2 diabetes or metabolic syndrome may do best on a very low-carb diet below 20 grams of net carbs per day. Advise them to sign up for the Diet Doctor two week low-carb challenge to get started.

Most low-carb doctors find that patients do best by jumping in with both feet and reducing their carbohydrates immediately (but please bear in mind any current medication they are taking). This seems to be the easiest, all or none, way to manage.

Except for perhaps a short bout of keto flu, they almost immediately feel better and notice significant results. This motivates them to continue to further their success.

Not All patients may be ready to jump in all at once. For more information about easing your patients into low carb, click here

Ease in?

Some patients, however, are not ready to do a strict low-carb diet, but may still benefit from carbohydrate restriction. Encourage your patients to make small changes such as reducing sugar in tea or coffee or replacing refined carbohydrates with fruits and vegetables. A little improvement may then motivate them to make more significant changes in the long run.

Reluctant patients can get started and achieve significant results by doing any or all of the following:

  • eliminating soft drinks, sports drinks, juice, and other sweet beverages
  • not adding sugar to coffee or tea.
  • not eating candy or sweets

These initial changes may have a positive impact on their blood sugar, their blood pressure and their waistline and leave them motivated to try more. Once they see positive changes, at the next appointment you can talk about building on their success.

Take it in stages

The next step is to reduce or eliminate their intake of refined carbohydrates, starches and grains in meals throughout the day. Encourage them to take the following actions:

  • Eliminate snacks containing starches and grains, such as chips, nachos, pretzels, popcorn. Ask them to name their favorite snacks. Discuss which ones have refined carbohydrates (some patients won't know.) Suggest other snacks such as nuts, seeds, olives, cheese and meats.
  • Eliminate starches and grains from their breakfast. If they usually start their day with a bowl of cereal or granola, or have toast, a pastry, or a croissant, suggest they stop and switch to bacon and eggs, or eggs and leftover veggies. This is an easy meal to explain why eating foods that rapidly turn to sugar is not a good idea.
  • Explain morning blood sugar highs. Many patients, particularly those with diabetes, know that blood sugar is highest in the morning. Eating food that converts to sugar first thing in the morning makes blood sugar even higher. Tell them it is like “pouring gasoline on a fire” to add more food that converts to sugar at this meal. Most will understand this.
  • Focus on what they can easily control. Most patients eat breakfast at home and have more control over their morning food options than they do at lunch and dinner. Suggest bacon, eggs, sausage and leftover veggies at breakfast. This may feel decadent and indulgent to them, but understanding how this effects their blood sugar will help convince them it is worth a try.
  • Reduce or eliminate starches and grains in their dinner meal. After eliminating carbohydrates at breakfast, the next step is to encourage patients to eliminate them at dinner. Most people make their dinner meals at home and have more control over what they are eating. Also, let them know it is more detrimental for them to consume carbohydrates and less likely they will burn off the sugar before bed time.
  • Reduce or eliminate starches and grains in their lunch meal. This last action can be the most challenging for patients. Quick options for low-carb lunch items may be difficult for some to find. Most cafeterias or restaurants cater to the traditional food pyramids with significant portions of carbohydrates. Suggest quick choices such as fast food meals of burgers without the bun, unadorned chicken wings, salads with meat and no croutons, deli meats with cheese but no bread. Once a patient develops stronger low-carb eating habits, lunch options will be easier for them to manage.


4. Sharing positive results and other health issues

Sharing positive results

Patients frequently focus on the scale to measure their success, but as healthcare professionals it is our job to point out all the non-scale victories. These can help keep the patient motivated and ensure long-term compliance and success.

  • If possible, record lean body mass and body fat percentage. Remark on any positive results.
  • Measure and record their waist circumference. Show them the before and after tape measurements and congratulate them on any positive change.
  • Track measures like fasting blood glucose, HbA1c, liver function, triglyceride and HDL. Can you make graphs to print it out for them to take home? Congratulate them on progress.

Sharing results with them and celebrating their successes keeps patients motivated to continue.

Patients already on medications and other safety issues

If your patient is already on diabetes medications, you may need to reduce the dose or completely eliminate the medication to prevent hypoglycemia. Insulin is the obvious example but there are others such as SGLT-2 inhibitors. Metformin is safe in the context of a low-carb diet.

In addition, low-carb diets can help lower blood pressure, especially if the patient is on BP medications. Make sure they can monitor their blood pressure at home and educate them about symptoms of hypotension such as dizziness, feeling weak or faint.

Occasionally a patient with type 2 diabetes starts a low-carb diet and loses weight but the blood glucose and HbA1c do not improve. Make sure it’s not a misdiagnosed case of insulin dependent or LADA (latent autoimmune diabetes in an adult)?

Addressing other health issues

With experience, you will soon feel very comfortable discussing low-carb diets with any patient with diabetes, obesity, or metabolic syndrome.

For other health concerns, it can feel more risky and unconventional to engage with patients in this manner. However, the more you see your own patients thrive on it, the more comfortable you will be suggesting it to others.

For a patient with conditions such as acne, migraines, joint pain, fibromyalgia, chronic fatigue, and others where anecdotal evidence but no controlled trials support the use of low-carb nutrition, consider addressing it this way: "This approach may help and likely won’t hurt. Would you like to try it and together we will see what happens?" At a minimum, they will end up replacing highly processed, refined carbohydrates with more wholesome options. Better health will likely result, even if it does not completely resolve all their symptoms.

Patients with cancer and other dire diagnoses

Although very preliminary. the scientific literature has demonstrated potential for strict low-carb diets to help improve treatment for certain types of cancers, in conjunction with traditional medical treatments such as surgery, radiation and chemotherapy. Lower blood glucose and insulin levels may help slow tumor growth and may make the cancer more susceptible to standard therapies.

Below you’ll find some of the research studies that support the potential role of a low-carb diet as an adjuvant treatment for certain cancers. However, this is still an early and unexplored research field. Much more research is needed to know what role, if any, a low-carb or keto diet might have in the future of cancer treatment. But, on the other hand, for a patient facing a potentially lethal diagnosis, we have to ask ourselves if the potential benefit could out weigh any potential risk.

Other diagnoses, such as multiple sclerosis, amyotrophic lateral sclerosis, Parkinson’s disease, mental health conditions, and Alzheimer’s disease, do not yet have a strong research base. Yet preliminary research on low-carb or keto diet applications suggest it may offer a glimmer of hope.

In conclusion

As a physician, you may find that discussing a low-carb or a keto diet provides a sense of hope and choice to a patient who feels like they have exhausted all options. And seeing patients improve with this “new” intervention tool can help invigorate your practice and your joy of helping others.

There are no guarantees. But it starts by taking the first step and asking:"A low-carb diet is an option we have not explored yet. There is a good chance it can hep, and it likely won't hurt. Would you like to try?"


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  1. Dr. Unwin has won a UK- National Health Service "Innovator of the Year" Award for his revolutionary work reversing type 2 diabetes in now hundreds of patients. He has created a highly-rated, 16-part video course for doctors with Diet Doctor. He reviewed this module for his input on effective patient engagement techniques.