Dr. Susan Raatz, a nutritional scientist with the United States Department of Agriculture (USDA) from the Grand Forks Human Nutrition Research Center, gave a lecture on satiety and weight management Thursday, Mar. 21 at the University of Manitoba.
The event was hosted by the department of human nutritional sciences as a part of Nutrition Month.
Raatz began her lecture with a data report from 2007-2009, which stated that 38 million males and 40 million females are obese in Canada, of which Manitoba has some of the highest obesity rates in Canada. She also discussed a U of M study, which was conducted in 2011 and found the numbers to be increasing, particularly among youth.
Raatz commented that the concept of weight management seems simple, but many people are failing to accomplish that balance. She said the interplay of genetics and the environment works against humans in maintaining a healthy weight. Food companies also work against individuals by marketing foods that do not satisfy hunger, causing consumers to eat and buy more of their product.
Raatz said the key to healthy eating and weight management is eating for satiety, a feeling of fullness, between one meal and the next, rather than overeating. She emphasized the importance of looking at the obesity epidemic from a nutritional perspective, rather than solely from a medical one.
An example she gave of eating for enhanced satiety is looking at the volume of food as well as its water content. A half cup of raisins contains the same volume as a cup and three-quarters of grapes, yet grapes are clearly the healthier choice.
Raatz also pointed to the importance of carbohydrates, protein, and fat in the diet. She said it is valuable to look at the fibre content of carbohydrates, since it increases satiety, but to also keep in mind there are different types of carbohydrates.
Many vegetables contain carbohydrates and are high in fibre. Whole grains are also a good source of dietary fibre.
Protein also enhances satiety, stated Raatz, but it is important to find lean sources of protein, such as chicken. Fat is very high in calories but enhances satiety, and is an important staple to the diet when it is a healthy fat, such as olive oil. Raatz emphasized the importance of monitoring how much of each of these is going into the body.
One individual in the audience raised the issue of food addiction. The individual claimed it is a debated medical diagnosis that medical professionals have been considering adding to the Diagnostic and Statistical Manual of Mental Disorders.
Raatz responded by expressing her belief that food addictions are more of a behavioural problem than a physiological one. The key to long-term success, she said, is to change behaviour by modifying the diet and changing the frame of mind regarding eating and activity. She said it is easy to mindlessly consume food, which makes an individual feel like they have lost control of their eating habits. Individuals may blame it on external factors rather than looking inside, changing the mindset, and regaining control.
“People don’t like to face up to behaviour. ‘The carbohydrate made me fat’ makes the issue external.”
Raatz said that there are various external factors involved in the process behind what we choose to eat. Society is exposed to easily accessible fast food and snacks that taste good and come in big portions. These foods are very high in fat and energy-dense, but low in nutrients.
According to Raatz, the social environment creates influences that affect the food choices we make. Those choices then eventually become habits, which can be hard to break.
Another important environmental factor involved in weight gain is the amount of time we spend sitting, noted Raatz. Increased caloric intake combined with high fat, high-density food low in nutrients is a recipe for weight gain.
Raatz also stressed the importance of education. She suggested allocating more money into education about nutrition rather than advertising for low-density foods.
“Education is key. We don’t even know how to cook anymore.”