Ways to prevent and manage overweight and obesity
Prevention and management of overweight and obesity is very complex and no single strategy or food can prevent or treat this disorder. Obesity prophylactics and its management is a question of energy balance. In order to experience any weight loss one should induce negative energy balance, that is, expend more energy than it is consumed from the diet. Of course, certain foods can easily bring about passive overconsumption of energy. These are foods that have high energy density (kcal/g), but low nutrient density (deficient in vitamins and minerals).
Dietary fat, sugars (from soft drinks and beverages), dietary fibre and water are the main factors that determine energy density of a given foods. The higher the water content of a food, the lower the energy density. Vegetables, soups and certain fruits, especially citrus fruits have low energy density, because they have high content of water that dilutes energy. Plain water does not provide any energy, but 1 g of fat/oil yields 9 kcal, because it does not contain water.
Dietary fibre (from whole grains and vegetables) will yield 1.5 kcal per gram. Carbohydrates and protein provide identical amount of energy, which is 4 kcal/g. 1 gram of alcohol/ethanol supplies 7 kcal. As can be seen, energy can easily be overconsumed with high-fat diets as well as when alcohol in ingested. Just a glass of beer (500 ml) provides 200 kcal. Unfortunately, to lose 200 kcal you need to walk briskly for about 60-80 minutes.
One thing that should be remembered is that alcohol is a priority fuel, which means that the body will always prefer to burn alcohol first, because it is harmful/poison and there is no place for its storage in our body. Just imagine you go to a wedding, where you are offered fatty food and alcohol.
Alcohol will be used to provide you energy to dance, while the energy from the fatty food will be deposited in the adipose tissue (fat cells) and wait for starving days (which will never occur) in order to be mobilised. Regrettably to write, these days we do not starve; on the contrary we are always feasting. We have to remember that there is limitation to the storage of carbohydrates and protein in our body, but such a limitation does not exist for fat.
To assist in the prevention and management of obesity, Nutritional Biochemists, Food Scientist, Nutritionists and Dietitians have classified foods according to their energy density. The first category consists of foods with very low energy density, that is, foods containing between 0.0 and 0.6 kcal/g. People are encouraged to eat as much as they wish of these foods, which include soups, fruits, and vegetables.
The second comprises of most foods that people eat daily, namely, starchy fruits and vegetables, beans, and lean meat. The general population may consume relatively large portions of these foods. The energy density for this category is between 0.6 and 1.5 kcal/g. The energy density of foods in the third category ranges from 1.5 to 4.0 kcal/g and consists of a wide variety of foods, such as cheese, salad dressings, some snack foods, and desserts. Intake of these foods, particularly those with higher energy density, should be moderated.
The energy density of foods in the fourth category ranges from 4.0 to 9.0 kcal/g. These foods have the highest energy density and include chocolates, fatty foods (e.g., nuts, chips, and other deep-fried foods), and candy. Intake of these foods requires careful portion control. There some strategies that may help to reduce the energy density of foods. They are as follows:
1) Try to incorporate a large portion of fruits and vegetables into meals. Choose spinach, cruciferous vegetables (vegetables of the cabbage family), tomatoes, citrus fruits, and melons, just to name a few. Broth-based soups, which are also low in energy density, are filling, low-calorie food choices. Also choose these foods as snacks and appetizers.
2) Round out meals by adding starchy fruits and vegetables, whole grains, legumes, lean meats, and low-fat dairy food. These foods are important for creating a healthy, balanced diet.
3) Consume infrequently, with particular attention to portion size, foods with little moisture, such as crackers, cookies, and chips as well as high-fat foods like croissants, margarine, and bacon. These foods provide a large number of calories relative to their weight and can easily be over-consumed. Foods such as nuts and olives, which have a relatively high amount of polyunsaturated and monounsaturated fatty acids, can be part of one’s diet as long as they are consumed in moderate portions.
4) Pay attention to portion sizes of fried foods, including vegetables; non-whole grains; dairy foods that are not reduced in fat; and fatty cuts of meat. These foods can be part of a healthy diet when consumed occasionally in small portions.
5) The energy density of many main dishes can be reduced by adding extra vegetables or by reducing the amount of added fat. Many different vegetables (e.g., chopped spinach, shredded carrots, diced green pepper, shredded zucchini, broccoli, or mushrooms) can be added to omelets, lasagna, pizza, chili, soups, and other hot dishes. Using lower fat meat and cheese or simply using less of the higher fat ingredients can reduce the fat content. This suggestion can be modified by incorporating typical tropical fruits and vegetables as well as other foods. I hope to be back soon with other assisting strategies. Enjoy your meals!
These are the thoughts of:
Sa’eed Halilu Bawa
Senior Lecturer (Associate Professor) at University of the West Indies, St. Augustine Campus, Trinidad.
Studied Food and Nutrition Sciences, Dietetics at Kaduna Polytechnic, Nigeria; Warsaw University of Life Sciences, Poland.