Nutrition Basics

Blood Sugar Ups and Downs

Does this sound like you?

"Carbohydrates make me gain weight. It seems like once I start eating them, I'm constantly hungry and need more."

Depending on the carbohydrate source, this statement holds some truth. Diets high in added sugar and refined carbohydrates can dramatically affect your blood sugar levels and leave you feeling hungry. These high blood sugar levels may also lead to increased weight gain over time.

How the body handles carbohydrates

After eating a carbohydrate-rich meal or snack, your body breaks this food down into small particles called glucose, or sugar. As the glucose level in your bloodstream rises, so does a hormone called insulin, which is produced by the pancreas. Insulin takes sugar out of the bloodstream and moves it into your cells, where it can be used for energy.

This wonderfully balanced system works well in most metabolically healthy individuals, but when you eat foods that are broken down and absorbed too quickly, blood sugar "swings" can greatly affect the way you feel and lead to weight gain over time, poor insulin response and diabetes.

Benefits to whole grains

The best way to control these feelings is not to cut out carbohydrates completely, but to choose carbohydrates that are broken down and converted into glucose slowly. Refined carbohydrates, or foods like white flour and sugar, are processed before you eat them. As a result, the body doesn't have to work as hard to digest them and they are rapidly turned into glucose.

Eating whole grain foods that have not been processed forces your body to work harder during digestion, which slows the rise in blood sugar. When blood sugar levels rise and fall at an even and gradual pace, you feel fuller longer, have more consistent energy and tend not to eat as often.

The bottom line: Eating too many refined carbohydrates, like processed breads and sugary sodas, causes rapid changes in blood sugars, making you feel hungry and leading you to overeat. Foods made with WHOLE grains (check the ingredients for "whole wheat" not just "wheat"), such as whole grain pasta, bread and cereals, can help maintain your blood sugar levels - and a healthy body weight, too.

Avoid Refined Carbohydrates

  • white bread
  • white rice
  • pasta
  • sugary cereals
  • sweets
  • jellies
  • candy
  • soda
  • juice
  • chocolate bars
  • granola & granola bars

Choose Whole Grains

  • 100% whole wheat bread
  • rolled & steel cut oats
  • brown rice
  • whole wheat pasta
  • popcorn
  • cornmeal
  • hulled barley
  • bulgur
  • buckwheat (kasha)
  • quinoa
  • millet
  • teff

Learn more about Brigham and Women's Hospital


For over a century, a leader in patient care, medical education and research, with expertise in virtually every specialty of medicine and surgery.

About BWH