Why Blood Sugar Spikes are Harmful and How to Moderate Them


Blood sugar spikes and crashes can be harmful to your health and should be avoided even if you are not diabetic.

Glucose level =  the amount of sugar in your bloodstream. (aka blood sugar)

All food raises your blood sugar. In this post we will be addressing foods that cause more extreme spikes in your blood sugar. In the diagram below the healthy rise in blood sugar is the stable line, staying between the normal high and low levels. They become unhealthy when they rise and fall past the normal levels.

When you eat a large amount of carbs such as spaghetti dinner with some bread, it is quickly broken down by your digestive system and a rush of sugar enters your blood. Your glucose levels spike up. Insulin is delivered and your glucose falls rapidly. Perhaps you need to take a nap. You feel tired, so you have something else to eat or have coffee. This shoots your glucose up again and you are on the blood sugar roller coaster.


Stable blood sugar keeps you feeling good.


This constant extreme up and down causes damage to your body and over time can cause insulin resistance. I will explain how that happens and how we can prevent it.

However, let’s have our science lesson first to understand blood sugar and insulin. Now, many kinds of foods may spike your blood sugar (such as caffeine, excess protein or fat, sugar, certain medications, also stress, lack of sleep and more -all of these to a lesser extent) but today we will just be addressing carbohydrates because it is the worst offender.




This is how our body is supposed to work

You eat a food containing carbohydrates. The starch is broken down into smaller parts (sugar). It immediately gets absorbed into the bloodstream. The sugar is supposed to move from the blood into your body’s cells. First, the blood goes through the pancreas which measures the amount of sugar in the blood. The beta cells in the pancreas release enough insulin to clear the sugar from the blood. It does this by releasing insulin  which “unlocks” your cells allowing the sugar to enter to be used for energy. This takes about 2 hrs. Then your blood sugar is back to normal.


If you are insulin resistant this is what happens

Gradually, without you even noticing, the insulin begins to have trouble unlocking the cells because the cells resist the unlocking action. Your pancreas sees the sugar not being cleared so it sends out more insulin forcing the cells to open. Eventually, it has to produce unnaturally high amounts of insulin.

Insulin resistance is silent. It presents no obvious symptoms.

You can be insulin resistant for  years before you show elevated blood sugar levels in your fasting glucose test. A better test for this is a measurement of your insulin levels.

Insulin resistance can be reversed.

You become pre-diabetic

Your blood sugar becomes higher than normal, but not high enough to be considered diabetes. Pre-diabetes can still be reversed.

This creates type 2 diabetes

There is too much sugar in your blood. Beta cells (cells in the pancreas that make insulin) keep making insulin. Over time, the beta cells becomes exhausted and can’t send out enough insulin anymore. Once beta cells lose their ability, it can’t be recovered. The sugar gets backed up in the blood, raising glucose levels. This results in diabetes. Diabetes can’t be cured, only controlled.

Recap:  normal 👉 insulin resistant 👉 pre-diabetic  👉diabetic


That’s how blood sugar and insulin work. Most Americans eat the Standard American Diet (SAD). This involves eating lots of simple carbs. Meals heavy in simple carbs spike our blood sugar. How much sugar is in the blood is proportional to the amount of carbs eaten. Then, after beta cells rush to send insulin, the blood sugar crashes to a low level, making us cranky and hungry, eating something sweet for a pick me up.




All this yo-yoing of your blood sugar is bad for your health.

Constant blood sugar highs and lows throughout the day cause…

  • irritability
  • fatigue
  • shakiness
  • poor concentration
  • dizziness
  • hunger
  • more carb cravings
  • energy fluctuations
  • weight gain
  • headaches
  • brain fog
  • mood swings
  • anxiety
  • damages your blood vessels
  • high sugar clogs your blood capillaries
  • sugar crashes starve your brain of needed fuel


But it doesn’t stop there, it hurts you in other ways as well. Over time this causes insulin resistance. Most people don’t know they are insulin resistant, because it doesn’t show up on your blood glucose test. They think everything is fine. These are all symptoms of insulin resistance.

  • The back and forth stresses your liver, pancreas and adrenals
  • Causes increased fat storage. Insulin is the strongest calorie storing hormone. Your fat cells stay sensitive to insulin. The insulin pushes calories into your fat cells. But it locks the cells so your body can’t use it for energy. This causes you to gain weight.
  • Triglycerides rise. This puts you at risk for atherosclerosis.
  • Lower HDL (good cholesterol)
  • Insulin stimulates the cholesterol forming enzyme which causes fatty build up on blood vessel walls.
  • Raises insulin. This also causes sodium retention.
  • Raises blood pressure.
  • Fibrinogen works harder making you more susceptible to blood clotting.
  • LDL (bad cholesterol) particles become more dense.
  • Makes artery walls less elastic.
  • Prone to metabolic syndrome* (see below for definition)
  • Causes hormonal imbalances that interfere with ovulation and make you prone to PCOS.**(see below)

It is worth noting that many people who are insulin resistant are not over weight. 1/3 of lean people with high blood pressure are insulin resistant.

Most insulin resistance and diabetes is from too much starch (carbohydrates), not sugar. About 7 times more carbs than sugar. Large amounts of carbs wear out the beta cells years before your blood sugar shows it. We can reverse this before the damage is done.

Our goal should be to keep our blood sugar stable through out the day. Blood sugar shouldn’t rise more than 40 points 2-3 hours after meal.

Reducing the speed at which carbs (broken down into sugar) get metabolized will get you off the roller coaster. This in turn will cause weight loss, lower blood sugar, lower insulin needs, lower risk of diabetes, lower triglycerides and higher HDL.

How do we do this? Ideally, not eating the carbs is the best way. But that is not always possible, nor do many of us want to cut out carbs completely. Most foods contain carbs. We also need carbs for our muscles, nervous system, cells and brain.

There is a way that we can temper blood sugar highs and lows to keep our blood sugar more stable and keep our bodies healthier.

Stay tuned…part 2  of this article will discuss easy ways we stabilize can our blood sugar.


*Metabolic syndrome– you are considered to have metabolic syndrome if you have 3 or more of the following: excess belly fat (40″ for men, 35″ for women), triglycerides over 150, HDL under 40, bp systolic (top) over 130, bp diastolic (bottom) over 85, fasting glucose over 100, insulin resistant

**PCOS– poly cystic ovary syndrome- hormonal imbalances, more male hormones (hair growth), overweight, acne, apple shape, high triglycerides, low HDL, high blood glucose level.



Bennett, Connie CHHC, Sugar Shock.

Wright, Hillary M.Ed, RD. The Pre-Diabetes Diet Plan

Thompson, Rob MD. The Sugar Blockers Diet

Williamson, Miryam Ehrlich. Blood Sugar Blues

2 thoughts on “Why Blood Sugar Spikes are Harmful and How to Moderate Them

  1. hope the audience for this post is far and wide and people really digest the concepts. Our food supply is riddled with refined carbs and processed foods, this is likely happening more often than most people think.

    Liked by 1 person

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