Most people believe diabetes is caused by eating too much sugar or gaining too much weight. It is often described as a disease of excess.

But in clinic, I increasingly see something that challenges this assumption.

Some patients developing diabetes are not overweight at all. In fact, many of them are quite slim.

This seems counterintuitive, but body weight does not necessarily reflect metabolic health. The real issue is how effectively the body processes and distributes energy. This phenomenon is sometimes referred to as “lean diabetes” — diabetes developing in people who appear slim or metabolically healthy.

Why Does This Happen?

After we eat, glucose enters the bloodstream. The body must move this glucose into cells where it can be used as energy. When this system functions well, blood sugar rises briefly and then returns to normal.

When metabolic regulation becomes less efficient, glucose remains circulating in the blood for longer periods. Over time, this contributes to insulin resistance and eventually diabetes.

In other words, the issue is not always how much sugar we eat, but how effectively the body processes and regulates it.

The TCM Perspective: Weak Metabolic Transformation

In clinical practice, slimmer individuals with rising blood sugar often show dysfunction within the Spleen–Kidney metabolic axis.

Spleen deficiency

The Spleen system governs transformation and transportation (脾主运化). It converts food into Qi and Blood and distributes nutrients throughout the body — functions comparable to digestion and metabolic processing.

When Spleen Qi weakens, nutrients are not efficiently transformed into usable energy. Metabolic by-products accumulate and circulate in an uncoordinated way — a pattern described in TCM as dampness arising from a weak Spleen system.

Patients with this pattern commonly experience:

• fatigue after meals despite eating lightly
• afternoon energy dips
• difficulty building muscle
• poor recovery after exercise

These patients may not overeat. The issue is that nutrients are not utilised efficiently.

Interesting Fact:

• Modern research offers a useful parallel. Some slim individuals may still accumulate visceral fat around their internal organs, even when their body weight appears normal. Visceral fat is known to impair insulin signalling and contribute to insulin resistance.

Kidney Yin deficiency

Another common pattern among slim diabetic patients is Kidney Yin deficiency.

In TCM theory, the Kidney system plays an important role in supporting the body’s metabolic functions. Chronic sleep deprivation, prolonged stress, aging, or years of overwork can gradually deplete Kidney Yin, leading to chronic inflammation and disrupted metabolism.

Patients may present with:

• persistent thirst despite drinking regularly
• dry mouth, especially in the evening
• poor sleep or frequent waking at night
• gradual decline in energy despite adequate rest

Interesting Fact:

• Modern research also shows that chronic low-grade inflammation can impair insulin sensitivity and disrupt metabolic balance. In TCM terms, this inflammation can sometimes be caused by internal heat from Yin deficiency.

Supporting Metabolic Balance

From a TCM perspective, treatment focuses on restoring metabolic regulation by supporting the Spleen and Kidney systems.

For Spleen deficiency patterns, helpful strategies include:

• maintaining regular meal timing
• avoiding overly processed foods that burden digestion
• engaging in regular exercise, including moderate resistance training
• incorporating traditional TCM foods such as Chinese yam (山药), lotus seeds (莲子), lentils (扁豆), kudzu root (葛根), and pumpkin (南瓜)

For Kidney Yin deficiency patterns, supportive measures include:

• maintaining consistent sleep timing and avoiding chronic late nights
• reducing long-term overwork and stress
• staying adequately hydrated
• incorporating nourishing TCM foods such as Dendrobium (石斛), goji berries (枸杞), Siberian Solomon’s seal (黄精), and mulberry (桑椹)

Evidence from Clinical Research

Modern research increasingly evaluates TCM therapies for metabolic disorders.

Meta-analyses of randomized trials report that acupuncture can improve fasting blood glucose, HbA1c, post-meal glucose levels, and insulin resistance in patients with type 2 diabetes.

Similarly, a network meta-analysis found that combining Chinese herbal therapy with conventional treatment reduced fasting blood glucose by about 2.17 mmol/L and post-meal glucose by about 1.94 mmol/L compared with standard therapy alone.

These findings suggest that integrative TCM therapies may support metabolic regulation alongside standard medical care.

Curious to explore the modern functional nutrition explanation behind this phenomenon?

Read our companion article:
The Lean Diabetic: Why Your Waistline Does Not Tell the Whole Story (FNT Perspective).

References

• Application of natural compounds in the treatment and prevention of prediabetes
• Effect of acupuncture for type 2 diabetes mellitus
• Efficacy and safety of traditional Chinese medicines combined with conventional Western medicines in the treatment of type 2 diabetes mellitus