Why Do I Feel Sick When I Eat Sugar?

Updated: Jun 2, 2020

So, you've been sticking to your diet diligently for a month or two and decide to have a decadent 'cheat' dessert.

It could be a sundae or a slice of cake, but instead of a pleasant sugar rush, you start to feel queasy.

Nausea, sinus congestion, sluggishness, stomach cramping, gas, and bloating can all be the consequence of your momentary indulgence. So why can't your body handle a little detour off your healthy diet?

There can be many potential causes of feeling sick after eating sugar - but here are the ones I see most.

a cupcake. text overlay saying why do i feel sick when I eat sugar?

Potential Causes

1. Intestinal Infection

Sugar, especially refined sugar, can feed opportunistic 'bad bacteria'.

This bacteria can then overgrow, creating an imbalance and making you sick (this is called small intestinal bacterial overgrowth - or SIBO).

Read: Small Intestinal Bacterial Overgrowth (SIBO)

Sugar can also feed yeast overgrowth in your intestinal tract (one kind of this type of infection is called candida).

In both cases you may have an underlying infection but you may not feel any symptoms until you eat sugar.

This especially applies to those who stop eating processed sugar for an extended period of time and then start again - like when you are on a healthy diet and have a 'cheat meal.'

When you temporarily stopped the sugar, the body started to function better and the infection had less fuel.

Once sugar was reintroduced, symptoms flare up because the infection is roaring back to life.

Symptoms of an Intestinal Infection

  • Dizziness

  • Head 'Fullness'

  • Sinus Congestion

  • Nausea

  • Stomach Cramping

  • Abdominal Pain

  • Gas

  • Rashes or Hives

  • Bloating

2. A Blood Sugar Issue

If your body is not using glucose properly, an 'overload' of sugar into your body will cause chaos.

These problems can range from insulin resistance to pre-diabetes to type II diabetes.

Blood sugar problems stem from the body's inability to utilize glucose in the blood stream.

In the case of insulin resistance, the body's cells cannot incorporate glucose easily which causes glucose to build up in the blood. This process can eventually lead to type II diabetes.

Testing will be required to confirm a diagnosis - the good news is that many blood sugar issues can be corrected through diet and lifestyle changes.

Symptoms of a Blood Sugar Problem

  • Feeling Faint

  • Nauseous

  • Shakiness

  • Anxiety

  • Fatigue

  • Irritability

  • Feeling sick when you are hungry

  • poor quality sleep

  • feeling nauseous in the morning

3. Inflammation Or An Underlying Condition

If you have an underlying condition, like rheumatoid arthritis, Raynaud's syndrome or vascular disease - the inflammation that excess sugar causes may inflame an underlying condition.