How Sugar and Refined Carbs Affect Insulin (and Why It’s Not a Problem for Everyone)

There's a lot of conflicting information out there on the internet and social media regarding cutting carbs and many fad diets with an approach that 'everyone' should follow. We are all different and understanding what's going on in our bodies is vital to enable us to pick out what's needed and what's not relevant to us.

1. What Happens After You Eat Sugar or Refined Carbs

• Sugars and refined carbohydrates (like bread, pastries, breakfast cereals) are digested quickly and break down into glucose (blood sugar).

• When blood glucose rises rapidly, the pancreas releases insulin, a hormone that helps move glucose from the bloodstream into cells for energy or storage. This is a normal and healthy process when occasional or moderate.

  
  

2. Repeated Spikes Can Lead to Higher Insulin & Changes in Insulin Sensitivity

• Eating high amounts of these foods frequently can cause sharp and repeated rises in blood sugar, requiring frequent insulin release.

• Over time, this persistent demand on insulin can make cells less responsive to it, a condition known as insulin resistance — where the body needs even more insulin to control blood sugar.

• Insulin resistance is a major risk factor for type 2 diabetes, obesity, and cardiovascular diseases.

Important nuance: Not everyone develops insulin resistance from eating carbs. Genetics, physical activity, body composition, overall diet quality, and other health factors influence how someone’s body handles sugar and refined carbohydrates.

3. Short-Term vs Long-Term Effects

• Short-term insulin rises are normal, especially after a meal that includes carbohydrates.

• Long-term chronic high sugar / refined carb intake is linked with persistent high insulin levels, insulin resistance, and metabolic problems — particularly when combined with excess calories and sedentary lifestyle.

  
  

Possible Negative Side Effects (Visible and Invisible)

A. Skin-Related Effects

There is evidence linking high sugar and refined carbohydrate intake with certain skin issues:

1. Acne & Breakouts

• Elevated insulin and related hormones like IGF-1 can increase oil (sebum) production in the skin and promote inflammation — both key contributors to acne and blocked pores.

• Some clinical studies show that high-glycaemic diets (lots of sugars/ refined carbs) are associated with more severe acne, while low-glycaemic diets improve skin condition.

  
  

2. Premature Skin Aging

• High blood glucose can form advanced glycation end products (AGEs) — compounds that damage collagen and elastin, the proteins that maintain skin elasticity and firmness.

• This process can contribute to wrinkles, sagging, and dull appearance.

  
  

3. Inflammation & Other Conditions

• A high-sugar diet can promote systemic inflammation and may worsen inflammatory skin conditions like eczema or psoriasis.

  
  

B. Other Visible and Invisible Effects

1. Weight Gain and Fat Accumulation

• Frequent insulin spikes promote fat storage — especially around the belly — and can contribute to overweight or obesity over time.

  
  

2. Energy Fluctuations & Mood Effects

• Quick rises and falls in blood sugar can lead to sensations of energy “highs” and “crashes,” mood swings, and cravings for more sugary foods.

  
  

3. Metabolic and Organ-Level Impacts

• Persistent high insulin and sugar levels are linked to:

  • Insulin resistance and type 2 diabetes risk,

  • Heart disease through inflammation and altered lipid metabolism,

  • Fatty liver development (non-alcoholic fatty liver disease),

  • Changes in gut microbiota and chronic low-grade inflammation.

    
    

Not Everyone Has Problems

It’s important to highlight that:

• Not everyone will develop insulin resistance or health problems from sugar or refined carbs.

• Many factors influence the impact: genetics, total calories, physical activity, overall dietary patterns, stress, sleep, and gut microbiota.

• Some people metabolize carbohydrates efficiently and maintain good blood sugar control with minimal negative effects.

In other words, occasional sugary treats won’t necessarily cause diabetes or visible health issues in everyone, but habitual high intake — especially of refined carbohydrates — raises risk.

References

Bessesen, D.H., 2001. The Role of Carbohydrates in Insulin Resistance. The Journal of Nutrition, 131(10), pp.2782S–2786S.

Visine, A. et al., 2024. Chronic and immediate refined carbohydrate consumption and facial attractiveness. PubMed.

Brand‐Miller, J. and You, J., 2012. Effect of the glycemic index of carbohydrates on acne vulgaris. PubMed.

Healthline, 2024. Does Sugar Cause Inflammation? Side Effects and More. Healthline.

Delibasi A. and Cakir E., 2014. Is refined carbohydrate consumption related to allergic diseases?. PubMed.