School of Medicine

Department of Genetics

Obesity and Diabetes

Christine A. Pollock R.N., Ph.D.
Jacqueline O. Favret, R.N., M.P.H

Doctors and researchers have found that obesity and diabetes are connected. Persons who are obese are at high risk for developing Type 2 diabetes (also known as "insulin-resistant" or "adult-onset" diabetes), particularly if a close family member is affected with diabetes. Therefore, it becomes very important to maintain a healthy body weight throughout your life in order to protect yourself from developing a chronic disease like diabetes.

As nurses associated with the Genetics of the Acadian People projects, we have been asked questions at public forums concerning obesity and diabetes. The following is a list of some of the most commonly asked questions, together with our answers and advice.

Is obesity caused by a specific genetic defect?
Researchers have not yet discovered a specific gene that causes obesity, although several genes are considered to be important in playing a part. However, we have come to understand that a person's genetic make-up can result in a predisposition to becoming obese. This means that a person may be particularly susceptible to becoming obese through experiencing risk factors in their life, like high calorie or high fat diets and lack of exercise. Your genetic make-up, which you have inherited from your parents, may contribute to your general body type, including how and where your body deposits fat in certain places such as buttocks or thighs. There seems to be a strong connection between abdominal fat and diabetes.

What, then, is the major cause of obesity?
The environment plays a much larger role in a person's likelihood of becoming obese than does any specific gene. By "environment," we mean not only what the outside world does to a person's body but also what enters a person's body through eating and drinking. The two main factors that can cause obesity are a diet high in fat and a lack of exercise. In Louisiana, like elsewhere in America, we think that we have many people who are obese for these two reasons: because their diet is high in fat content and do not exercise.

Everybody in my family is fat. Can I assume that I am predisposed to being obese?
Not necessarily. Genetics play a small role in body weight. The most important factors will be the foods that you eat every day and the amount and type of exercise you do. 

How do I know if I am overweight or obese when all of my family is heavy?
Dieticians have developed a formula to calculate a number, called your BMI (Body Mass Index), which they use to make this decision. The formula is:

BMI = Weight/height2 
(Weight measured in kilograms and height measured in meters)

The following numbers are good indicators of whether are not you are overweight.

  • Underweight = BMI of 19.8 or less
  • Normal Weight = BMI of 26.0
  • overweight = BMI of 26.0-29.0
  • obese = BMI over 29.0

How can I determine if my diet is causing obesity in my family and myself?
One good way to find out is to keep a food diary for a week. You should write down the time, the amount, and the type of food you eat throughout the day. Be sure to include liquids as well as solid food, such as beer, soft drinks, fruit juices, etc. You will need to write down the fat grams and calories for each food item. Add these up each day. If the amounts are too high, then you can be fairly sure that your diet is a factor in causing obesity in yourself and in your family.

What is "too high"? How many calories and fat grams can I eat every day and not gain weight?
This number may vary according to your gender, age and body frame. However, there are some guidelines that have been developed by professionals that may help you determine how much to eat to maintain an ideal weight. In general, an adult woman should eat about 1500 calories a day and an adult male about 2500 calories. Your diet should not have more than 35% fat, which is about 35 grams of fat each day. If you are interested in determining your caloric and fat gram needs, you can refer to the many reference books and pamphlets available, or you could ask your health care provider. We have provided some web site addresses at the end of this chapter where you can obtain this information. 

How can I know the calories and fat grams when I eat food from a fast-food place?
Most fast-food chains, such as Burger King, Subway, McDonalds, Taco Bell, and Domino's Pizza have this information available for you on request. This information can also be obtained in small booklets that are available in some grocery stores, bookstores, through some organizations such as Weight Watchers, and by accessing Internet resources, including the ones listed at the end of this chapter. 

What types of foods should I eat every day?
The most important guideline is to have a balanced diet. A balanced diet contains protein, grains, fruits and vegetables and only a small amount of fat. The majority of your diet should consist of carbohydrates (like whole grain bread, rice, cereal) and fruits and vegetables. The best types of meat are those that are low in fat, like chicken, fish, and lean red meats.

My family really likes Cajun foods. What can I do to make these healthier?
Fortunately, Cajun cooking includes many fresh vegetables and spices that are healthy for you and your family. If you are using any meat to flavor your vegetables, use only lean meats. Avoid using lard and bacon fat. The best way to prepare meats is by grilling or roasting and not by frying foods in fat or oil. If you need to fry some foods, use vegetable oil instead of butter or lard. Boiled seafood is healthier than fried seafood and can be made very tasty by using Cajun spices. For dessert, add fresh fruit to small portions of low fat or fat-free desserts.

Is there a pill I can take to help me lose weight?
There are many pills being sold that promise miraculous results by helping you control your appetite and lose weight. However, many of these pills are ineffective--They do not help people lose weight. Even worse, many of these pills have negative side effects that can cause serious health problems, like heart problems. Researchers have shown that when people stop taking pills to help them lose weight they gain back the weight they had lost. The best and healthiest program for losing weight is to eat a nutritious balanced diet and exercise regularly. Such a program may require some changes in your lifestyle.

What type of exercise is best?
The most important thing to remember about exercise is that it should be done on a regular basis, which means about three times a week for 30 minutes each time. To encourage yourself to exercise regularly, you should choose an activity or set of exercises that you enjoy. For instance, walking is an excellent exercise for most people. However, in Louisiana where our summers are hot and humid, walking outside should be done when it is cool, such as early in the morning or in the evening. Many people like to walking in the shopping malls or other indoor facilities in order to get their exercise on a regular basis. Swimming is also a good exercise that many people enjoy. Other activities many people enjoy include dancing, jogging, and sports. 

Can I pass the family tendency to be overweight on to my children?
Researchers have determined that only a slight predisposition for obesity is inherited. The best way for children to avoid being overweight is to eat a diet that is balanced and is low fat. Their diet should consist of lots of fresh fruit and vegetables. Snacks like chips, cookies, ice cream, and soft drinks should be limited. Again, this may require a lifestyle change in your family. It is very important that all children become involved in physical activities on a daily basis. Too many of children spend their free time in front of computers, television, and video games, and this results in a growing number children who are obese and who will likely suffer medical consequences of obesity as adults. 

What are some of the health problems my family and I can have if we are overweight or obese?
People who are overweight or obese have a greater chance of having heart disease, diabetes, cancer, muscular and skeletal problems, and a variety of other health problems. 

I know a lot of people who have diabetes, but I don't really understand what the disease involves. What exactly is diabetes?
The disease we typically call "diabetes" is known as Diabetes Mellitus. It has been known for centuries, and it is known to run in families.

Diabetes Mellitus is a disease of high blood sugar. It is dangerous, even fatal, to have too much or too little sugar in the blood. The level of sugar in a person's blood is very important in maintaining day-to-day and even minute-to-minute health, and one of the body's major functions is to control blood sugar at proper levels. Controlling blood sugar involves the liver, pancreas, kidneys, and fat. It's the pancreas that lowers blood sugar by producing a hormone known as insulin. Insulin removes sugar from the blood and forces it into cells, where it is used to make energy for the body.

There are two types of diabetes, Type 1 and Type 2. People who have Type 1 diabetes do not produce enough (or any) insulin and need to take insulin injections every day to help regulate their blood sugar levels. This type of diabetes is also known as Insulin-Dependent Diabetes Mellitus (IDDM). People with Type 2 diabetes produce insulin, but the cells of the body cannot respond properly to insulin. This type of diabetes is also known as Non-Insulin Dependent Diabetes Mellitus (NIDDM), and this is the type of the disease that a person has when he or she is "insulin resistant." Many chronic health problems can occur to individuals with diabetes, especially if the blood sugar levels are not controlled. These problems include kidney failure, blindness, and problems in blood circulation, which may lead to amputations. 

My mother has diabetes. Does that mean that I will become a diabetic?
In order to become a diabetic, two factors need to be present. First, you need to inherit a predisposition to the disease, and second, the environment must trigger a response in your body. Your genes alone are not enough. This has been shown in studies of groups of identical twins: When one of a pair of twins develops diabetes, there is only a slightly increased chance that the other sibling will develop the disease. Because identical twins are identical genetically, the environment of the individual must play a role in the development of diabetes. However, because both genetics and environment are typically shared by family members, we recognize that persons with a family history of diabetes have a greater risk for developing the disease.

It would be important to know what type of diabetes you mother has. Type 1 diabetes has a strong genetic component that appears to involve several different genes. It is formally called "Juvenile Diabetes", and it is the second most common childhood illness in developing countries. It is thought that people need to inherit genes from both parents in order to get Type 1 diabetes. Some environmental risk factors thought to play a role in triggering the development of Type 1 diabetes are such things as cold weather, exposure to viruses, being Caucasian, and infant diet (having formula and an early introduction of foods). 

Individuals who get diabetes later in life get Type 2 diabetes. Type 2 diabetes used to be called "Adult Diabetes," but, unfortunately, we see many younger people, particularly those who are obese, developing this disease. There are two main risk factors for getting Type 2 diabetes: obesity and a family history of the disease. A family history of Type 2 diabetes is one of the strongest risk factors for getting the disease, especially if the person eats a diet high in fat with too little carbohydrates and fiber and if they get too little exercise. Type 2 diabetes is common in people who have these habits and uncommon in people who do not, even though they have a high genetic risk. Obesity is a very strong risk factor for getting Type 2 diabetes, especially if the person became obese at an early age or if the obesity has lasted a long time. 

What is the chance that my children will become diabetic?
This is difficult to say, because there are so many factors involved. If you have Type 1 diabetes, the chance that your child will get diabetes is about 1 in 20. This risk is slightly less if you are female. This risk is doubled if both parents have diabetes or if you developed diabetes before the age of 11. Tests can be done to determine the risk status of your children, and these tests include finding out the body's response to glucose and measuring if there are any antibodies to insulin.

Type 2 diabetes runs in families, both due to learned behaviors, such as eating high fat foods and not exercising, and also to genetic factors. The chances of your child getting diabetes is approximately 1 in 7 if you were diagnosed before the age of 50 and 1 in 13 if you were older than 50. However, if both you and your partner have diabetes, the risk is 1 in 2 that your children will become diabetic. If your child has a high risk for developing diabetes, it is important that good food and exercise habits are followed to avoid obesity. 

How can I tell if I am developing diabetes?
One of the easiest ways to determine if you are developing diabetes is to have either your blood or urine tested for sugar. The results will be higher than normal if you have developed this disease. In addition, you may develop some specific symptoms that would suggest that you need to have your blood or urine tested for sugar levels. These symptoms include increased thirst, unexplained weight loss, excessive hunger, and frequent urination. You also need to consider any factors that would increase your risk, like advanced age, sedentary lifestyle, high blood pressure. Some special risks for developing Type 2 diabetes involve pregnanacy: If you are a woman who has been pregnant, who is developing gestational diabetes, or who is having a baby weighing more than ten pounds.

If you have any concerns about whether you have diabetes, you should talk to your health care provider as soon as possible. This condition is very serious and needs to be identified and treated according to what is specific to you and your body. The sooner you visit your health care provider, the healthier the rest of your life will be.

For more information, contact the authors at the following addresses:

Christine A. Pollock

Jacqueline O. Favret

How to Learn More

This is the American Diabetic Association website. It contains basic information about diabetes, as well as current news on health issues related to diabetes, local diabetic information, recipes for diabetics, and a section on health living.

This is the site for the American Obesity Association, whose main mission is education, research and community action. There are a variety of topics including information on obesity, treatment, and medical conditions associated with obesity. Membership applications are offered on this site.

This is the site for the Orion Township Public Library. Access the Public Library and they click on "useful internet sites" and then click on the "medicine and health care" section for various health information on a variety of topics, including "Ask the Doctor", nutrition and fitness, and diabetes. In the nutrition and fitness section, you can find out the nutritional values of all foods, including fast foods.