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 increase their exercise has made many physicians pessimistic about therapeutic lifestyle interventions.

However, for many low-carb doctors, teaching patients to begin a new lifestyle intervention has become the most rewarding part of their medical practice. What used to be frustrating and demoralizing — trying to help 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 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:

You can find more about the science supporting carbohydrate restriction for these conditions and others in our Science of low carb and keto guide.

Who may benefit: Encouraging scientific evidence

Less well-established, but still encouraging, evidence suggests we may be able to treat the following conditions as well:

Who else might benefit: Anecdotal or preliminary evidence

Many people report significant improvements in other health conditions using a 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 changes, effects of ketones, or other factors. It may be worth saying to patients, however, “There is only preliminary evidence that this might help your condition. Would you like to try?

These conditions include:


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, or indications of other chronic diseases.
  • Weight gain since their last appointment, despite efforts to lose weight using other 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; or amenorrhea, weight gain, or hirsutism from PCOS. For some of the conditions for which there is only preliminary evidence — acne, sleep apnea, migraines, heart burn, mental health conditions — patients may be eager to try using low carb rather than begin taking medications or using other invasive therapies.
  • 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 sugars and starches.

While we can’t magically give you more time in your patient visit, here are some suggestions about how to offer lifestyle suggestions in a way that may make patients more receptive.

Collaboration and motivation

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 may 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, breathe 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 lifestyle coaching, behavioral counseling, and motivational interviewing. More than 5000 published journal articles, videos and organizations discuss the effectiveness of motivational interviewing and give specific tips and techniques.

The support for this approach to patient engagement is strong, even if its use has been limited in the past to a “calories in-calories out (CICO)” model of “eat low fat” and “eat less, move more.” Engaging patients with low-carb information in this empowering style has the potential to achieve 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 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 the realistic steps the patient 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, along with 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 in order to …?“; “Do you want to hear about other options to treat …?“; or “Can I talk to you about some lifestyle changes that might help you …?
    • 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 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?” or “What do you think about that?
    • Affirming abilities: Offer statements and gestures that recognize patients’ strengths and acknowledge positive behaviors, no matter how big or small. Affirmations build confidence in patients’ ability to change. These can be simple statements such as, “That is a great suggestion” and “You did really well with that.” The affirmations are even more important when the patient comes back to see you in a few weeks. Be sure to acknowledge success: “You have made great progress.
    • Reflective listening: Hearing what patients tell you and then paraphrasing it back to them shows you are listening. Language that shows you are paying attention can move them in a positive direction: “I hear you saying that …,” or “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 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.

First, listen to what 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 some tangible steps for reducing carb intake 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, and other topics. That is where Diet Doctor comes in. We hope to be a reliable and trustworthy source for the in-depth knowledge your patents might want or need.

This is why we have some advice for how to address carbohydrate restriction in a time-efficient and effective manner. We recommend helping patients understand the glycemic burden that carbohydrate foods place on the body as equivalents of teaspoons or cubes of sugar. This method can provide a powerful, memorable and actionable explanation for patients in a very short time.

Most patients understand that sugar is not good for them. Many, however, do not understand that many carbohydrate foods — including fruit, whole grains, and other foods usually considered to be “healthy” — break down into glucose in the body. Patients are often surprised to learn that these foods, once digested, can be compared to an equivalent amount 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. The simple act of physically adding a number of cubes to their underestimates can drive home the message that many carbohydrate foods break down into sugar with digestion.

Dr. Unwin and other low-carb doctors in the UK have created powerful visual aids that show common carbohydrate foods as equivalent teaspoons of sugar. These guides are endorsed by the UK’s National Institute for Health Care and Excellence and are available through the Public Health Collaboration. Doctors can download these visual aids to use in their clinics. One look at these infographics, like the one below, and patients usually quickly get the concept.

The effect of foods on blood glucose2
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


By quickly demonstrating, with the visual guide or with a jar of sugar cubes, how much sugar patients are consuming from carbohydrates, you can dramatically illustrate the impact carbs are having on their blood sugar and show how they can reduce their sugar load.

For example by showing patients 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. This provides a powerful visual to encourage 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 cream, if necessary for palatability) instead.
  • If lunch is a sandwich with deli meat, how about salad with sliced chicken or steak and 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 and 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 and suggest drinking sugarless tea, coffee or water and snacking on nuts and cheese. Berries with unsweetened whipping cream or full fat yogurt can substitute for a sugary dessert.

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. Advising patients to sign up for Diet Doctor’s two week low-carb challenge can get them started.

Most low-carb doctors find patients do best by jumping in with both feet and reducing their carbohydrates immediately. (All doctors must bear in mind any current medications patients are taking, especially blood glucose-lowering ones.) All-or-none seems to be the easiest way for most patients to manage.

Except for perhaps a short bout of keto flu, most patients feel better almost immediately and notice significant positive changes in their health. This motivates them to continue their success.

However, not all patients may be ready to jump in all at once. For more information about easing your patients into low carb, click below.

Ease in?

Some patients are not ready to do a strict low-carb diet, but may still benefit from carbohydrate restriction. Encourage these 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 blood sugar, blood pressure, and waist circumference, leaving patients motivated to try more. Once they begin to see positive changes, you can talk about building on their success at the next appointment.

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. These might be foods such as chips, nachos, pretzels, or popcorn. Ask patients 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 breakfast. If patients usually start the day with a bowl of cereal, toast, pastry, or croissant, suggest they stop and switch to bacon and eggs or eggs and leftover veggies. You can use this simple meal switch to explain why eating foods that rapidly turn to sugar is not a good idea.
    • 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 affects their blood sugar may 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.
    • 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 rely on traditional food guidance and the convenience of many carbohydrate foods by serving 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, or 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.

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 patients motivated and ensure long-term compliance and success.

      • If possible, record lean body mass and body fat percentage. Remark on any improvements.
      • Measure and record waist circumference. Show patients before and after tape measurements and congratulate them on any positive change.
      • Track measures like fasting blood glucose, HbA1c, liver function, triglyceride, and high-density lipoprotein (HDL) cholesterol. Can you make graphs to print out for patients to take home? Congratulate them on progress.

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

4. Other health issues

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. In contrast, metformin is safe in the context of a low-carb diet.

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

Occasionally a patient with type 2 diabetes starts a low-carb diet and loses weight, but blood glucose and HbA1c levels do not improve. In these cases, make sure you are not dealing with a misdiagnosed case of insulin-dependent diabetes or latent autoimmune diabetes in an adult (LADA).

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 riskier and unconventional to engage with patients in this manner. However, the more you see patients thrive with this approach, the more comfortable you will become using it.

For a patient with acne, migraines, joint pain, fibromyalgia, chronic fatigue, and other conditions 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, patients may end up replacing highly processed, refined carbohydrates with more wholesome options. Better health may result, even if this approach 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 adjunct or adjuvant treatment for certain cancers. However, this is still an early and mostly 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 life-shortening diagnosis, we have to ask ourselves — and should consider discussing with patients — the possibility that potential benefit could outweigh 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 suggests these diets may one day prove beneficial to these patients.

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 patients who feel 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 help, and it likely won’t hurt. Would you like to try?


Back to main low carb for doctors guide

  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 input on effective patient engagement techniques.

  2. This visual aid comes from The Journal of Insulin Resistance article, “It’s the glycemic response to, not the carbohydrate content of food that matters in diabetes and obesity: The glycemic index revisited” (Unwin, Haslam & Livesy, 2016). It shows the glycemic load reinterpreted as 4-gram teaspoons of sugar.