If junk food contains carbohydrates, your sugar level will likely rise. During digestion, the body converts carbohydrates into glucose, the body's main source of energy. This blood sugar then moves from the intestines into the bloodstream, where it's made available -- with the help of insulin -- for cell absorption.
Blood Sugar
After eating almost anything, your blood sugar will rise. Normally, this signals the pancreas to release insulin into your bloodstream. It's this hormone that makes it possible for the glucose to move from your blood into your cells where it's then used for energy to fuel bodily functions. When the body is unable to use this insulin, or doesn't produce enough of it to meet your needs, problems can occur, and it's often an indication of prediabetes or diabetes.
Carbohydrates
Eating junk food high in carbohydrates will elevate your blood sugar. However, whether the carbs you eat are from junk food or healthy food, all carbohydrates act the same. According to the Cleveland Clinic, foods high in sugar do not raise blood sugar levels any more than foods high in starches. For example, 15 g of carbs from a sugar-sweetened cookie is going to raise your blood sugar the same as 15 g of carbs from a slice of bread. The same can be said for 15 g of carbs from a bag of chips, a banana, a potato or even a glass of milk.
Sugar Alcohol
Sugar alcohols are sweeteners sometimes found in sugar-free junk food, particularly in candies, cookies and sodas. These additives don't metabolize at the same rate as standard carbohydrates, like sugar or starch, so they don't necessarily raise blood sugar at the same rate. But they're still considered carbs and can affect your blood sugar -- just not to the same degree. As a general rule, the grams of carbs from sugar alcohol are worth half of that from sugar or starch, explains the American Diabetes Association.
Testing
Most people have a fasting blood sugar -- or a glucose level after not eating for at least eight hours -- of below 100 mg per deciliter of blood, or mg/dL. When fasting blood sugar reaches 100 mg/dL, you're often considered prediabetic. It isn't until fasting blood sugar is over 125 mg/dL that you're diagnosed with diabetes, according to the American Diabetes Association.
Another method used to measure blood sugar is something known as a random blood sugar test. Unlike fasting blood sugar, it's not dependent on when you last ate. Most people have a blood sugar level of less than 140 mg/dL, notes the Mayo Clinic. Anywhere between this number and 199 mg/dL is considered prediabetes, while anything over 199 mg/dL is considered diabetes.
Management
If you're not prediabetic, diabetic or at risk of developing either condition, you don't usually need to monitor your blood sugar levels. Your pancreas releases enough insulin to move glucose from the blood into your cells. If, however, you're overweight or obese, sedentary or inactive and carry most of your body fat through the abdomen, you're at a greater risk of developing prediabetes or diabetes. Losing weight, becoming more active and eating healthier foods can all help to prevent the development of both prediabetes and type 2 diabetes.
References
- Mayo Clinic; Prediabetes; January 2011
- MayoClinic; Diabetes; May 2011
- American Diabetes Association: How to Tell if You Have Prediabetes
- American Diabetes Association: Checking Your Blood Glucose
- Cleveland Clinic: Carbohydrates and Blood Sugar Control for People with Diabetes
- American Diabetes Association: Sugar Alcohols
