Diabetes Core Update – Special Edition: Obesity as a Chronic Disease (Feb 2026)

Date: February 23, 2026
Host: Dr. Neil Skolnik (A)
Guests: Dr. Donna Ryan (B), Dr. Susan Kucera (C)

Episode Overview

This special edition of Diabetes Core Update explores the transformation of obesity from a mere risk factor into a recognized chronic disease with far-reaching implications for primary care and diabetes management. Dr. Neil Skolnik, with renowned obesity researcher Dr. Donna Ryan and medical educator Dr. Susan Kucera, delves into the latest science, clinical frameworks, shifting attitudes, and actionable guidance for clinicians. The episode confronts outdated perceptions, explains critical biological mechanisms, and addresses practical questions around diagnosis, stigma, and treatment—including the impact of GLP1 receptor agonists.

Main Discussion Points & Insights

1. Obesity's Changing Status: From Risk Factor to Treatable Disease

• Key idea: In the last five years, advances in pharmacotherapy (GLP1 and GIP agonists) have revolutionized obesity care, moving it firmly into the category of a chronic disease physicians are expected to treat routinely—not just mention as a risk factor.
  • “Obesity has changed from a risk factor that we talk about with patients to a critical disease that we treat.” (A, 00:18)
  • These therapies not only induce significant weight loss but deliver “improved health outcomes, not just weight loss,” affecting blood pressure, lipids, glucose, and comorbidities (obstructive sleep apnea, fatty liver, cardiovascular disease). (A, 01:12)

2. Understanding the Obesity Epidemic: Environmental Drivers

• Obesity prevalence has surged: ~15% in 1975, ~35% by 2005, ~40% today (with another 30% overweight). (A, 05:44)
• Chief causes: Environmental shifts, not genetic changes.
  • “The genes have not changed. What's changed is the environment… the two big changes in the food environment and the physical activity environment really deserve the credit or the blame.” (B, 06:55)
  • Ultra-processed foods, fast food culture, and reduced physical activity are central: “Today, 60% of the average American diet is fast food. It's ultra processed foods.” (B, 08:04)
• The US has exported its “obesogenic lifestyle” globally, fueling a worldwide epidemic. (B, 09:57)

3. Biological Underpinnings: Obesity as a Chronic Disease

• Pathophysiology:
  • Research in the 1990s (Hirsch, Leibel, Rosenbaum) revealed “metabolic adaptation”: losing weight lowers metabolic rate more than expected, making weight maintenance very challenging. (B, 10:43; 11:26)
  • Appetite hormones drive increased hunger and reward-seeking behavior post-weight loss—seen as lasting for a year or more (Sumithran et al., 2011). (B, 12:13)
  • Quote: “The body's in this reduced state… it makes you want to eat more and also on your energy expenditure… you have a lower resting metabolic rate.” (B, 12:48)
  • Clinical relevance: These biological defenses explain why both losing weight and sustaining weight loss are so difficult. The problem is not one of willpower.
• Patient understanding and stigma:
  • Many patients express relief: “So you mean it’s not my fault.” (A, 13:16)
  • Dr. Kucera: Patients often accept the chronic disease framing faster than clinicians and are more open to discussing medical and behavioral therapy. (C, 13:42)

4. Clinician Attitudes & Implications for Care

• Many doctors still view obesity as a lifestyle issue:

  • Over 50% of surveyed physicians do not consider obesity as a chronic disease; 40% believe patients could lose weight if they “just tried hard enough.” (A, 14:26)
  • Dr. Skolnik: This ignores the complex biology and hormonal regulation that undermine simple “calories in, calories out” logic. (A, 14:45)
  • Dr. Kucera: “There is an important lifestyle component to this, like any chronic disease. But I think the truth is, you know, to be non-judgmental physicians, we have to embrace this and move forward with it.” (C, 16:15)

• Donna Ryan: Medications are appropriate and necessary: "You must fight biology with biology." (B, 17:29)

5. Updated Definitions: Beyond BMI—Lancet Commission & Measurement

• Lancet Commission (2025): Advocates redefining obesity beyond BMI:
  • BMI is a measure of body size, not health or fat distribution. (B, 19:10)
  • Use additional tools: percent body fat (via DEXA, impedance), waist circumference, and waist-to-height ratio (visceral fat as more predictive of risk).
  • Dr. Skolnik: Waist circumference and waist-to-height ratio capture many at-risk patients missed by BMI—especially "normal-weight obese" individuals. (A, 21:50)
    • “A waist to height ratio of greater than 0.5 is an even more sensitive measure.”
  • Dr. Kucera notes the challenge of practical implementation but endorses body fat and visceral fat measures as useful for patient education. (C, 22:57)
• Clinical vs. preclinical obesity:
  • The commission recommends distinguishing between people with obesity complications (clinical obesity) and those with excess fat but no complications (preclinical obesity).
  • Dr. Ryan is skeptical about some criteria and exclusion of diabetes but sees value in refining risk identification. (B, 25:48)

6. Stigma, Responsibility, and the Chronic Disease Model

• Addressing the criticism: “Labeling obesity a chronic disease removes patient responsibility.”

  • Dr. Kucera: Every chronic disease—diabetes, hypertension, depression—has a lifestyle component, but we do not make it solely about responsibility or blame. (C, 28:46)
  • “We have to be really careful not to use that language because it puts stigma around something that we ask all of our patients to do no matter what chronic disease we're helping them manage.” (C, 29:10)

• Integrated approach: Obesity care is not "either/or" (lifestyle vs. medication), it is "and": use all appropriate modalities. (A, 30:00)

7. Final Thoughts & Key Takeaways

• Dr. Kucera: Framing obesity as a chronic disease “gives us a framework that we're really used to using in primary care… structure this in a framework that we can know how to work with.” (C, 30:43)
• Dr. Ryan: Medications are game-changing and deliver far more than weight loss: “They have independent effects on glycemia. They reduce inflammation…we need to take them seriously.” (B, 31:26)
• Dr. Skolnik: This new understanding supports destigmatizing the disease, supports both preventative and medical interventions, and enables better patient outcomes.

Notable Quotes & Memorable Moments

• "Once you gain weight, it is very difficult to lose it and keep it off." (B, 08:12)
• “Metabolic adaptation…when you reduce your weight by 10%, your metabolic rate decreases by more than 10%.” (B, 11:26)
• “So you mean it's not my fault.” (A, 13:16)
• “You must fight biology with biology.” (B, 17:29)
• “BMI…doesn't really say anything about body health…we know…excess abnormal body fat contributes to…cardiometabolic parameters.” (B, 19:10)
• “Formalizing it as a chronic disease gives us a framework that we're really used to using in primary care.” (C, 27:04)
• “We need to treat the disease as a disease. As Dr. Ryan said, treating biology with biology.” (A, 32:12)

Key Timestamps

| Timestamp | Segment | |------------|-------------------------------------------------------------------------------| | 00:18 | Shift in obesity care: risk factor → chronic disease, therapeutic advances | | 05:44 | Data on increasing US obesity prevalence | | 06:55 | Donna Ryan: environmental vs. genetic causes | | 10:43 | Pathophysiology: metabolic adaptation, hormonal changes, defense of body weight| | 13:16 | Patient stigma, "So you mean it's not my fault" | | 14:26 | Survey: many doctors don’t recognize obesity as chronic disease | | 16:15 | Dr. Kucera: Complexity, biology, and non-judgmental care | | 17:29 | "Fight biology with biology"—rationale for medication | | 19:10 | Lancet Commission: shifting beyond BMI | | 21:50 | Waist circumference & waist-to-height ratio: practical clinical measures | | 22:57 | Dr. Kucera: Implementation barriers and patient education opportunities | | 25:48 | Preclinical vs. clinical obesity: value & controversy | | 28:46 | Addressing "personal responsibility" and stigma | | 30:43 | Final frameworks for primary care | | 31:26 | Medications’ broader health impacts |

Conclusion

This episode delivers a thorough, clinician-centric exploration of how obesity should now be seen, measured, discussed, and treated—as a complex, chronic, and common disease, tightly interwoven with diabetes and cardiometabolic health. New pharmacotherapies provide tools to fight biological defenses against weight loss. The panel urges physicians to move beyond outdated models, destigmatize care, embrace new definitions (beyond BMI), and educate patients with compassion and honesty.

Summary Message:
“Treat biology with biology…and treat the disease as a disease.”

For more resources, visit www.diabetesjournals.org.