Recommend lifestyle interventions for weight management with Dr. Will Yancy, Director of the Duke Lifestyle and Weight Management Center and Interim Chief of Division of General Internal Medicine at Duke (@DrWillYancy). Learn about the ketogenic diet, lower carbohydrate diets, and exercise, and their impacts on your patients.
BMI is still commonly used clinically but can fall short for a patient who may be more (or less) muscular than average. And BMI cutoffs are lower for Asians than for Westerners. E.g., for South Asians, BMI > 22.9 is considered overweight.
Vital signs matter – as patients exercise more, a lower resting heart rate means their heart is becoming more efficient.
Dr. Yancy finds it’s easiest to use the umbilicus level to measure waist circumference, and strive to measure it every time you see the patient, and the patient can spin to wrap the tape themselves!
Per Dr. Yancy, fasting insulin levels > 8-10 µU/mL indicate insulin resistance.
Weight goals for patients are patient-dependent – goals could be to fit in certain clothes, move more easily or become eligible for surgery, not necessarily a number.
Ask a 24-hour recall from patients on what they are eating… without judging!
Low carb diet (typically under 20-50 grams per day) is popularly referred to as ketogenic diet. Dr. Yancy notes <20 grams carbs per day will put most patients in ketosis.
Reduce insulin dose by half upon starting a low carbohydrate diet to prevent hypoglycemia.
Technically no carb foods (meat, poultry, fish, eggs) are unlimited but that does not mean a patient should eat them or add fats indiscriminately. Recommend telling patients to eat to satiated and not beyond.
If drinking, lower carbohydrate alcohols are better.
Intermittent fasting has evidence to help with weight loss and metabolism.
Weight Management – Show Notes
Obesity has emerged as a global epidemic with profound implications for public health and individual well-being. As internal medicine physicians, we are on the front lines of combating this multifaceted issue that contributes to a range of serious health conditions, including diabetes, cardiovascular disease, and certain cancers. In this discussion, we will focus on a comprehensive approach to obesity management, highlighting the importance of diagnosis, physical examination, and lifestyle interventions, with a specific emphasis on the low-carb diet as a valuable tool in our arsenal.
BMI Measurements: The first step in diagnosing obesity is a thorough assessment of body mass index (BMI). It is a simple, yet effective, tool to categorize patients into different weight classes (World Health Organization, 2000). BMI is calculated by dividing weight (in kilograms) by height squared (in meters). The following classifications should be noted:
Underweight: BMI < 18.5
Normal weight: BMI 18.5 – 24.9
Overweight: BMI 25 – 29.9
Obesity Class I: BMI 30 – 34.9
Obesity Class II: BMI 35 – 39.9
Obesity Class III: BMI ≥ 40
Physical Signs: Physical examination should also include vital signs and waist circumference
Waist Circumference: While BMI provides a general assessment of obesity, measuring waist circumference can help assess visceral fat. Individuals with excess visceral fat are at higher risk for metabolic complications. A waist circumference >40 inches (102 cm) in men and >35 inches (88 cm) in women should raise suspicion of visceral obesity (World Health Organization, 2008).
One of the most effective lifestyle interventions for obesity management is the adoption of a low-carbohydrate diet. This dietary approach restricts the intake of high glycemic index carbohydrates, emphasizing whole foods rich in healthy fats, protein, and fiber. Numerous studies have demonstrated its efficacy in weight loss, improvement in insulin sensitivity, and reduction in cardiovascular risk factors (Hallberg et al., 2018; Saslow et al., 2017).
Implementation: Encourage patients to reduce their intake of refined sugars, processed foods, and grains while increasing consumption of vegetables, proteins, and fats. A macronutrient composition of approximately 20-50 grams of net carbohydrates per day is commonly recommended.
Benefits: Low-carb diets have been shown to promote weight loss by reducing appetite and enhancing fat utilization for energy. They also have favorable effects on blood sugar control, lipid profiles, and blood pressure (Bueno et al., 2013).
Monitoring: Regularly monitor patients’ progress, including weight, fasting glucose levels, and lipid profiles. Adjust the dietary plan accordingly to optimize results.
Medication adjustments: Low-carb diets can reduce blood glucose immediately so insulin or sulfonylureas should be reduced at onset– typically half the usual dose if blood glucose is near goal to begin with. Further reductions are often necessary as weight goes down. Low-carb diets can also lead to diuresis and natriuresis so water and salt replenishment are important, and/or diuretic medications can be reduced. SGLT2 inhibitors should be used with caution because the risk for euglycemic ketoacidosis may be increased.
Intermittent fasting (IF) has gained significant attention in recent years as a dietary strategy with potential health benefits. This approach involves alternating between periods of fasting and eating. Types include alternate day, 5:2 and time-restricted eating. Research suggests that intermittent fasting may have a positive impact on weight management, metabolic health, and longevity. A review by Tinsley and La Bounty (2015) found that intermittent fasting could be an effective method for reducing body fat and preserving lean muscle mass. Another review by Patterson and Sears (2017) explored the potential benefits of intermittent fasting in improving insulin sensitivity and reducing the risk of type 2 diabetes. Furthermore, research by Mattson et al. (2017) delved into the cellular and molecular mechanisms through which intermittent fasting may promote brain health and protect against neurodegenerative diseases. As internal medicine physicians, it’s essential to stay informed about the growing body of evidence on intermittent fasting and consider it as part of our recommendations for patients seeking weight management and improved metabolic health. Further research with long-term follow up should continue to inform these discussions.
World Health Organization. (2000). Obesity: Preventing and Managing the Global Epidemic. Report of a WHO Consultation (WHO Technical Report Series 894). Link
World Health Organization. (2008). Waist Circumference and Waist-Hip Ratio: Report of a WHO Expert Consultation. Link
Hartvigsen, M. S., et al. (2019). Investigating the Role of Rare and Low-Frequency Variants in Lipodystrophy. Journal of Clinical Endocrinology & Metabolism, 104(12), 6148-6158.
Hallberg, S. J., et al. (2018). Effectiveness and Safety of a Novel Care Model for the Management of Type 2 Diabetes at 1 Year: An Open-Label, Non-Randomized, Controlled Study. Diabetes Therapy, 10(2), 341-368. Link
Saslow, L. R., et al. (2017). An Online Intervention Comparing a Very Low-Carbohydrate Ketogenic Diet and Lifestyle Recommendations Versus a Plate Method Diet in Overweight Individuals With Type 2 Diabetes: A Randomized Controlled Trial. Journal of Medical Internet Research, 19(2), e36. Link
Bueno, N. B., et al. (2013). Very-Low-Carbohydrate Ketogenic Diet v. Low-Fat Diet for Long-Term Weight Loss: A Meta-Analysis of Randomised Controlled Trials. British Journal of Nutrition, 110(7), 1178-1187. Link
Goal and Learning Objectives
Listeners will develop understanding on what lifestyle interventions can help with successful weight loss and be able to discuss diet, exercise and other strategies with patients.
After listening to this episode listeners will…
Be able to get an effective history from a patient on all things lifestyle – what they eat, what they do for exercise and how they manage their stressors
Provide patients with a dietary plan for effective weight loss
Know how to use lifestyle interventions in combination with medications
Dr Yancy reports prior consulting fee with Foodminds (relationships ended). The Curbsiders report no relevant financial disclosures.
Syed FZ, Yancy Jr. WS, Williams PN, Watto MF. “#412 Low Carb, Keto, Fasting: Lifestyle Interventions for Weight Management”. The Curbsiders Internal Medicine Podcast. thecurbsiders.com/category/curbsiders-podcast October 16, 2023.
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Producer and writer: Fatima Syed, MD, MSc, FACP Show Notes, Infographic, and Cover Art: Fatima Syed, MD, MSc, FACP Hosts: Matthew Watto MD, FACP; Paul Williams MD, FACP Reviewer: Emi Okamoto, MD Showrunners: Matthew Watto MD, FACP; Paul Williams MD, FACP Technical Production: PodPaste Guest: Will Yancy, MD