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1. Nutrition

1. Nutrition and body weight
2. Nutrition, exercise, and type 2 diabetes
3. Nutrition and disease
4. Nutrition and the stress response

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Nutrition and body weight

One of Dr. Raine's collaborators at the University of Alberta, Dr. Linda McCargar, looks at body weight on an individual rather than a societal level. She examines the physiological factors that influence body weight, and her specific interests are metabolic rate (the rate at which the body uses energy) and body composition (the relative proportions of bone, lean and fat tissue in the body). These are influenced by three major contributing factors: diet, physical activity, and disease.

These three factors and the roles they play are key to all of Dr. McCargar's research. In one project she surveys Alberta teens about their body weight, nutritional habits, and physical activity. In another project, she works with patients who have cancer or diabetes to determine the effects of diet and physical activity, as well as the role played by the disease.

One of Dr. McCargar's new areas of interest is sarcopenic obesity, which occurs in people with low muscle mass who also have a high percentage of body fat. Improved equipment for accurately measuring body composition has led to a clear description of this new subgroup, which most commonly includes older people. "Studies suggest that low muscle mass is detrimental to health and functional status; and these individuals can have difficulty with activities of daily living," explains Dr. McCargar. "We already know that high body fat is associated with health risks; so when the two are combined, it is an even greater concern."

Throughout her career Dr. McCargar's overriding interest has been finding strategies for successful weight loss. "We know that certain dietary treatments work well in the short term, but how to sustain weight loss is still not well established." She explains that the little information available suggests that continued vigilance regarding diet and physical activity is the answer—a message that can be difficult to hear for people who have struggled for many years to lose weight. "We want to know if there are alternative ways to maintain a healthy weight, perhaps by adding more variety to your physical activity patterns or to your dietary patterns?"

Looking at both weight loss and weight gain gives Dr. McCargar a broader picture of the factors at work. "It is often thought that metabolic rate is reduced in situations of overweight and increased in situations of underweight, but that doesn't necessarily seem to be the case," she explains, adding that a number of variables seems to be in play.

"When it comes to nutrition, we know so much more than we did ten years ago," says Dr. McCargar. "And with public interest so high, it's a very exciting time to be working in this field."