Oct 21 / Star Khechara

How Dietary Fat Causes Insulin Resistance and Skin Ageing

Understanding Insulin Resistance

Insulin resistance occurs when the body’s cells no longer respond efficiently to insulin, the hormone that moves glucose from the bloodstream into the cells for energy. When this process falters, blood sugar remains elevated, resulting in hyperglycaemia and a chain reaction of inflammation, oxidative stress, and glycation.

For skincare professionals, insulin resistance is not just a metabolic concern; it’s a dermatological one. The skin often reflects internal metabolic imbalance, and understanding this connection can transform how practitioners approach chronic skin conditions and premature ageing.

Meat, dairy & High-Fat Food = Insulin Resistance

Low-Fat, High-Carb, Plant-Based Food = Insulin Sensitivity

...a low-fat, plant-based, whole-food diet containing approximately 10% fat outperformed a conventional diabetes diet based on the 2003 American Diabetes Association guidelines.
Diabetes Care. 2006

Rosacea: The Inflammatory Link

Research shows that people with rosacea exhibit an over-expression of pro-inflammatory cytokines such as IL-1, IL-8, and TNF-α, all of which are closely associated with insulin resistance, type 2 diabetes, and obesity. The rate of insulin resistance among rosacea patients is significantly higher than in control groups, suggesting that metabolic inflammation is a key underlying factor.

By addressing insulin resistance through dietary and lifestyle changes, practitioners can help reduce systemic inflammation and improve rosacea outcomes from within.

Psoriasis: Adipose Imbalance and Chronic Inflammation

Being overweight or obese is a well-known risk factor for psoriasis, largely due to the role of adipocytokines, signalling molecules secreted by fat tissue. In both psoriasis and insulin resistance, the balance of leptin and adiponectin (the hormones that regulate insulin sensitivity) is disrupted.

Inflammatory cytokines like TNF-α and IL-1β drive the rapid production of keratinocytes. Tumour Necrosis Factor alpha leads to decreased Keratinocyte apoptosis and cell cycling, which causes hyperproliferation of the epidermis.
In postmenopausal women, higher baseline HOMA-IR levels were significantly associated with higher incidence of psoriasis over 21-year cumulative follow-up
Archives of Dermatological Research. 2022

Acne and Insulin Resistance

Acne patients regularly have high blood glucose levels, high insulin levels and insulin resistance. Hyperglycaemia activates the IGF-1/mTORC1 pathway, which leads to excess sebum production and overgrowth of keratinocytes, which block the hair follicles, both of which are hallmarks of Acne formation.

Skin Tags: A Visible Marker of Insulin Dysfunction

Skin tags are often considered harmless, but they may serve as an early diagnostic sign of insulin resistance. They commonly appear after age 40, particularly in women, and are strongly linked with obesity and metabolic imbalance.

The proposed mechanism involves elevated IGF-1 (Insulin-like Growth Factor 1) resulting from hyperglycaemia. IGF-1 binds to receptors in keratinocytes, triggering overgrowth in the epidermis that manifests as skin tags. Recognising this link allows practitioners to identify and address systemic insulin issues before more serious metabolic complications develop.

Skin Ageing: The Metabolic Accelerator

Insulin resistance accelerates biological ageing through several mechanisms.

  • Telomere Shortening
  • Mitochondrial Dysfunction
  • Inflammation / inflammaging
  • And (via the mechanism of Hyperglycaemia) Endogenous Glycation


It also drives to collagen and elastin fibres, forming Advanced Glycation End Products (AGEs).

AGEs stiffen collagen, impair elasticity, and trigger pigment accumulation, resulting in thinner, more wrinkled, and sallow skin. This internal ageing pathway underscores why addressing insulin resistance is essential for maintaining youthful, resilient skin.

Skin Ageing: The Metabolic Accelerator

A landmark Diabetes Care (2006) study found that a low-fat, whole-food, plant-based diet containing around 10% fat outperformed the conventional diabetes diet in improving insulin sensitivity. By reducing dietary fat, clients can lower insulin resistance, stabilise blood glucose, and restore both metabolic and skin health.

For skincare professionals, this represents a powerful opportunity to educate clients: beautiful, youthful skin begins with metabolic balance.

References

  1. Book: Mastering Diabetes
  2. Vessby, B., Uusitupa, M., Hermansen, K., Riccardi, G., Rivellese, A., Tapsell, L., Nälsén, C., Berglund, L., Louheranta, A., Rasmussen, B., Calvert, G., Maffetone, A., Pedersen, E., Gustafsson, I., & Storlien, L. (2001). Substituting dietary saturated for monounsaturated fat impairs insulin sensitivity in healthy men and women: The KANWU study. Diabetologia, 44(3), 312-319.
  3. Barnard, N.D., Cohen, .J., Jenkins, D.J., Turner-McGrievy, .G., Gloede, .L., Green, .A., & Ferdowsian, .H. (2009). A low-fat vegan diet and a conventional diabetes diet in the treatment of type 2 diabetes: a randomized, controlled, 74-wk clinical trial. The American Journal of Clinical Nutrition, 89(5),
  4. Guenther Boden; Role of Fatty Acids in the Pathogenesis of Insulin Resistance and NIDDM. Diabetes 1 January 1997; 46 (1): 3–10
  5. M. Roden et al., “Mechanism of Free Fatty Acid-Induced Insulin Resistance in Humans.” The Journal of Clinical Investigation 97, no. 12 (June 15, 1996): 2859–65.
  6. Howard A. Wolpert et al., “Dietary Fat Acutely Increases Glucose Concentrations and Insulin Requirements in Patients with Type 1 Diabetes Implications for Carbohydrate-Based Bolus Dose Calculation and Intensive Diabetes Management.” Diabetes Care 36, no. 4 (April 1, 2013): 810–16
  7. Kirstine J. Bell et al., “Impact of Fat, Protein, and Glycemic Index on Postprandial Glucose Control in Type 1 Diabetes: Implications for Intensive Diabetes Management in the Continuous Glucose Monitoring Era.” Diabetes Care 38, no. 6 (June 1, 2015): 1008–15
  8. https://nutritionfacts.org/video/what-causes-insulin-resistance/
  9. Wright, N., Wilson, L., Smith, M. et al. The BROAD study: A randomised controlled trial using a whole food plant-based diet in the community for obesity, ischaemic heart disease or diabetes. Nutr & Diabetes 7, e256 (2017)
  10. Danby, F William. "Turning acne on/off via mTORC1." Experimental Dermatology 22.7 (2013): 505-506.
  11. Dario Giugliano, Antonio Ceriello, Katherine Esposito The Effects of Diet on Inflammation: Emphasis on the Metabolic Syndrome, Journal of the American College of Cardiology, Volume 48, Issue 4, 2006, Pages 677-685, ISSN 0735-1097

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Article by Star Khechara

Professional agehacker, author, speaker, founder of skin nutrition institute
About me
Ex-skincare formulator and beauty author turned skin-nutrition educator: Star distilled her 20+ years of skin-health knowledge into the world’s first international accredited skin-nutrition school to teach skin therapists, facialists, face yoga practitioners and estheticians how to help their clients feed the skin from within for cellular-level rejuvenation and vibrant beauty. 
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