What is gestational diabetes?
Gestational diabetes mellitus is a condition in which a hormone made by the placenta prevents the body from using insulin effectively. Glucose builds up in the blood instead of being absorbed by the cells.
Unlike type 1 diabetes, gestational diabetes is not caused by a lack of insulin, but by other hormones produced during pregnancy that can make insulin less effective, a condition referred to as insulin resistance. Gestational diabetic symptoms disappear following delivery. Approximately 3 to 8 percent of all pregnant women in the United States are diagnosed with gestational diabetes.
What causes gestational diabetes?
Although the cause of gestational diabetes is not known, there are some theories as to why the condition occurs. The placenta supplies a growing fetus with nutrients and water and also produces a variety of hormones to maintain the pregnancy. Some of these hormones (estrogen, cortisol, and human placental lactogen) can have a blocking effect on insulin. This is called the contra-insulin effect, which usually begins about 20 to 24 weeks into the pregnancy.
As the placenta grows, more of these hormones are produced, and the risk of insulin resistance becomes greater. Normally, the pancreas is able to make additional insulin to overcome insulin resistance, but when the production of insulin is not enough to overcome the effect of the placental hormones, gestational diabetes results.
Gestational diabetes that’s not carefully managed can lead to high blood sugar levels. High blood sugar can cause problems for you and your baby, including an increased likelihood of needing surgery to deliver (C-section).
Complications that may affect your baby
If you have gestational diabetes, your baby may be at increased risk of:
- Excessive birth weight. If your blood sugar level is higher than the standard range, it can cause your baby to grow too large. Very large babies — those who weigh 9 pounds or more — are more likely to become wedged in the birth canal, have birth injuries, or need a C-section birth.
- Early (preterm) birth. High blood sugar may increase the risk of early labor and delivery before the due date. Or early delivery may be recommended because the baby is large.
- Serious breathing difficulties. Babies born early may experience respiratory distress syndrome — a condition that makes breathing difficult.
- Low blood sugar (hypoglycemia). Sometimes babies have low blood sugar (hypoglycemia) shortly after birth. Severe episodes of hypoglycemia may cause seizures in the baby. Prompt feedings and sometimes an intravenous glucose solution can return the baby’s blood sugar level to normal.
- Obesity and type 2 diabetes later in life. Babies have a higher risk of developing obesity and type 2 diabetes later in life.
- Stillbirth. Untreated gestational diabetes can result in a baby’s death either before or shortly after birth.
What is a gestational diabetes diet?
A Gestational diabetes diet is a diet plan designed for women with gestational diabetes who do NOT take insulin. Eating a healthy diet is an important part of a treatment plan for gestational diabetes. A healthy diet includes a balance of foods from all the food groups, giving you the nutrients, vitamins, and minerals you need for a healthy pregnancy. For women with gestational diabetes, eating a balanced diet also helps to keep blood sugar levels in the healthy target range. Following a meal plan and eating a healthy diet is a key part of managing gestational diabetes. It is essential that you work with your health care provider to create a plan for your healthy diet. The information in this booklet is for women who have been diagnosed with gestational diabetes. These guidelines are not appropriate for all pregnant women.
- Carbohydrates are part of a healthy diet for a woman with gestational diabetes.
- Carbohydrates are nutrients that come from certain foods, like grains, milk and yogurt, fruits, and starchy vegetables.
- During digestion, your body breaks down most carbohydrates into simple sugars, which are your body’s main source of energy.
- Eating carbohydrates increase your blood sugar level. If you eat a small amount of carbohydrates at a meal, your blood sugar level goes up a small amount. If you eat a large amount of carbohydrates at a meal, your blood sugar level goes up a large amount.
- You need to find a balance between eating enough carbohydrates to get the energy and glucose you need, and limiting the carbohydrates you eat to control your blood sugar level. The best way to do this is to spread them throughout the day.
- Your health care team will come up with a healthy diet for you that includes the right amount of carbohydrates to maintain a healthy pregnancy.
- Women with gestational diabetes usually need to avoid foods that are high in sugar, like sweets and desserts, in order to keep their blood sugar level in control.
- Not getting enough carbohydrates can also cause problems. You should follow the meal plan provided by your health care provider.
Balancing your diet
- All foods contain some combination of carbohydrates, fat, and protein. Fat and protein affect your blood glucose over many hours, but carbohydrate affects it much faster. For this reason, you will need to regulate your intake of foods that are rich in carbohydrates (“carbs”). Your healthcare provider will show you how and your meal plan will help you stay on track.
- It is important to make healthy food choices. Nutritious foods support your baby’s growth and development, help control your gestational diabetes and keep you feeling well.
- Controlling your gestational diabetes requires controlling the pattern of your eating. Your meal plan gives you targets for when to eat and how much to eat.
Steps to get started
- Begin Counting Carbohydrates. To manage your blood sugar you will learn a technique called “carbohydrate (“carb”) counting”. This system helps you balance your meals and snacks throughout the day. Begin by reading the Nutrition Facts labels for “Total Carbohydrates”. Your target will likely be 30-45 grams for meals and 15-30 grams for snacks.
- Eat smaller amounts of carbohydrates at each meal. Rather than eating a large amount of carbohydrates at a single meal, spread out your carbohydrates throughout the day. Eating carbohydrates directly affects your blood sugar level, so eating a smaller amount of carbohydrates at regular intervals throughout the day will help keep your blood sugar from rising too high after a meal.
- Eat small, frequent meals and snacks. Eat about every 2 to 3 hours. Because you are eating fewer carbohydrates in your meals, you will need to eat more frequently in order to meet your daily nutritional needs. Plan at least 3 meals and 3 snacks a day.
- Include protein at meals and snacks. Your protein needs to increase during your last trimester. Protein may help even out your blood glucose. It may also help you feel more satisfied throughout the day.
- Eat a very small breakfast, with a similar mid-morning snack about 2 hours later. Blood glucose levels tend to be higher in the morning. To offset this, your meal plan will probably include fewer carbs at breakfast than at lunch or dinner.
- Have a nighttime snack. It is good to eat a snack before you go to sleep to keep your blood sugar at a healthy level overnight. Some examples of healthy snacks include Greek yogurt, an apple with peanut butter, or whole-grain crackers with cheese. Choose high-fiber foods. Good sources include whole-grain bread and cereals, fresh and frozen vegetables, and beans. Fruits can also be a good source of fiber — most plans include fruit in afternoon or evening meals and snacks.
- Watch out for sugar and concentrated sweets.
o Do not drink fruit juice. Plan to get your fruit servings later in the day (not at breakfast). Although fruits are a healthy source of carbohydrates, their carbs are easily absorbed and tend to raise blood glucose levels quickly.
o Avoid regular soft drinks, fruit juice, and fruit drinks. High-carbohydrate drinks like these raise your blood glucose quickly.
o Limit desserts such as ice cream, pies, cakes, and cookies. These foods often have large amounts of added sugar, honey, or other sweeteners.
o Read labels carefully and check them for total carbohydrates per serving.
- Be careful about fat
o Consume lean protein foods, such as poultry and fish. Avoid high-fat meats, lunch meat, bacon, sausage, and hot dogs.
o Remove all visible fat by removing the skin of poultry and trimming the fat from meat.
o Bake, broil, steam, boil, or grill foods.
o Avoid frying. If you do fry foods, use nonstick pans, vegetable oil spray, or small amounts (1 to 2 teaspoons) of oil.
o Use skim or low-fat (1%) milk and dairy products.
o Limit or avoid adding extra fat, such as butter, margarine, sour cream, mayonnaise, avocados, cream, cream cheese, salad dressing, or nuts.
o Limit convenience foods. These are often higher in carbohydrates, fat, and sodium.
o Avoid instant noodles, canned soup, instant potatoes, frozen meals, and packaged foods.
How Effective Are Gestational Diabetes Diets
Studies have shown gestational diabetes diets to be effective in the management of gestational diabetes. Several different types of dietary approaches are used globally, and there is no consensus among the various professional groups as to what constitutes an ideal approach. The conventional approach of limiting carbohydrates at the cost of increasing energy from the fat source may not be the most optimal. Instead, allowing higher levels of complex, low-to-medium glycemic index carbohydrates and adequate fiber through higher consumption of vegetables and fruits seems more beneficial.
Further studies have also shown that increased physical activity, improved diet, and lower stress perception reduced BMI, postpartum diabetes status improved metabolic outcomes, and reduced the risk of preterm deliveries and low birth weight.