More or Less – Is RFK Jr Right About China's Diabetes Rate?

Podcast: More or Less
Host: Tim Harford, BBC Radio 4
Guest: Professor Diana Magliano
Episode Date: November 8, 2025

Episode Overview

This episode investigates recent claims by US Health Secretary Robert F. Kennedy Jr. about the prevalence of diabetes in China and among American children. Host Tim Harford, with input from diabetes epidemiologist Professor Diana Magliano, fact-checks RFK Jr.'s numbers, reviews global diabetes statistics, and discusses trends in diabetes diagnoses worldwide.

Key Discussion Points and Insights

1. RFK Jr.’s Claim Under the Microscope

• RFK Jr.’s Assertions ([01:44] & [04:51]):

  • Claimed a dramatic rise in juvenile diabetes: From a rare condition for pediatricians to 1 in 3 kids currently being prediabetic or diabetic in the US.
  • Stated, “Twenty years ago there was no diabetes in China. Today, 50% of the population is diabetic.”

• Immediate Reaction

  • Tim Harford: “[RFK Jr.'s] 50% figure can't possibly be right,” ([04:57]).
  • Calculations show if China’s rate were 50%, global diabetes figures would be mathematically impossible.

2. Explaining Diabetes and Its Types

• Professor Diana Magliano ([02:41]):
  • Differentiates Type 1 (autoimmune, insulin absent) and Type 2 (insulin resistance, lifestyle-related) diabetes.
  • “If you don't have insulin, you will die.” ([03:00])
  • 90% of global diabetes cases are Type 2 ([03:22]).

3. Risk Factors and Genetic Predisposition

• Obesity is a major driver, but not the sole factor ([03:47]).
• Certain populations, especially those from Asia, India, Pakistan, and indigenous groups, have higher genetic risk ([04:01]).

4. The Real Numbers: China and Global Context

• Current Diabetes Prevalence in China

  • Professor Magliano: “No, it's at about 12%.” ([05:21])
  • 2000: Less than 1% Chinese adults with diabetes.
  • Latest figures: 11.9% of adults aged 20–79 are diabetic ([05:52]).
  • Rise is significant, but not remotely close to 50%.
  • Urbanization and lifestyle change are major contributors.

• Global Perspective

  • 590 million people worldwide with diabetes—“likely an underestimate” ([04:18]).
  • Highest prevalence: Pakistan (~30–31%), some Pacific islands even higher ([06:27]).
  • Example: Nauru’s diabetes prevalence reached 34% overall, and 50% in some older groups after rapid socio-economic changes ([06:46]).

5. Trends in Prevalence and Incidence

• In middle- and low-income countries, the burden is growing due to genetic and lifestyle factors ([07:24]).
• In high-income countries, new cases are stabilizing, but the overall prevalence is up because patients are living longer ([07:57]):
  • “Prevalence is generally rising everywhere because we're living longer with diabetes, because we're managing it so much better.” – Prof. Magliano

6. Diabetes in Children and Adolescents

• RFK Jr.'s American Child Statistic
  • Tim Harford: 1 in 3 American children aged 12–17 are prediabetic—CDC data ([08:40]).
  • But: 70% of prediabetic teens will not develop diabetes ([08:40]).
• Actual pediatric Type 2 diabetes rate:
  • Professor Magliano: “It's really low. For type 2, it's 0.67 in 1000,” or 1 in 1,500 children under 20 ([09:14]).
• Observation: Diagnoses occurring younger in high-income Asian countries (Japan, Korea), less so in white European populations ([08:21]).

7. Signs of Hope

• “We can be cautiously optimistic that in at least high income countries we’re managing to turn the tide.” ([09:36])
• Increased awareness and better management are helping contain—or even reduce—new Type 2 diabetes cases, even if overall prevalence keeps rising as people live longer.

Notable Quotes and Memorable Moments

• On RFK Jr.'s China claim:
  • Tim Harford ([04:57]): “That would mean 700 million people in China have diabetes and … the rest of the world has negative 100 million diabetics. Now, I'm not a doctor, but that doesn't seem very likely.”
  • Prof. Magliano ([05:21]): “No, it's at about 12%.”
• Historical change in China:
  • Prof. Magliano ([05:52]): “In 2000, it was under 1% of people in China would have diabetes. And now … 11.9% of Chinese adults aged 20 to 79 have diabetes.”
• On the alarming pace in Nauru:
  • Prof. Magliano ([06:46]): “So their diabetes prevalence hit 34% overall and it was 50% in some of the older age groups.”
• On trends:
  • Tim Harford ([07:40]): “Although the percentage of people who have diabetes is growing, the rate of new cases is stabilising and in some places reducing.”
• Re: US children’s actual numbers:
  • Prof. Magliano ([09:14]): “It's really low. For type 2, it's 0.67 in 1000.”
• On progress:
  • Prof. Magliano ([09:36]): “We can be cautiously optimistic that in at least high income countries we’re managing to turn the tide.”

Key Timestamps

• RFK Jr’s claim and host’s response: [01:44] – [04:57]
• Explanation of diabetes types: [02:41] – [03:22]
• Population risk factors: [03:47] – [04:18]
• World diabetes statistics and China fact-check: [04:18] – [06:07]
• Highest global diabetes rates: [06:27]
• Case Study: Nauru: [06:46]
• National and regional trends: [07:24] – [07:57]
• Children and prediabetes in the US: [08:35] – [09:18]
• Hopeful note on managing diabetes: [09:36]

Summary

Tim Harford and Professor Diana Magliano rigorously debunk RFK Jr.'s claim that half of China’s population is diabetic—it's actually around 12%, a steep rise from 1% in 2000, but dramatically lower than stated. While the global number of people with diabetes is unprecedented, most cases are Type 2 and country prevalence varies widely. In the US, while 1 in 3 teenagers are prediabetic, only a fraction will develop diabetes, and actual pediatric Type 2 rates are much lower than suggested. Globally, high-income countries are stabilising new cases through better management and awareness, offering some hope for the future.