A growing obesity issue

Sylvia Santosa, Canada Research Chair in Clinical Nutrition, and associate professor in the Department of Health, Kinesiology and Applied Physiology, leads a team of researchers at the centre’s Metabolism, Obesity, and Nutrition (MON) lab and is taking a cell-to-body approach to understand what makes someone with obesity more or less susceptible to metabolic disease and weight gain.

“We really want to know what it is about where fat tissue is stored in the body that might promote a greater risk of disease, as well as what affects those characteristics,” says Santosa.

The timing or duration of obesity may have something to do with the cells. “Understanding how our interindividual differences might affect our metabolism or fat tissue can potentially help promote more individualized treatment and treatment targets for the prevention of disease.”

Santosa’s team also conducts clinical research. One of her studies aims to determine how to set up better nutrition requirements for bariatric surgery patients — people who have parts of their stomach, and in some cases their intestines, removed to restrict the amount of food or calories they can ingest. The evidence on which postsurgery nutrition recommendations are based, Santosa explains, is minimal. “If we are able to understand the nutritional needs of individuals, then maybe it can help them in terms of recovery and weight maintenance post-surgery.”

Some of Santosa’s team’s findings to date support existing evidence that people living with obesity since childhood differ greatly from those who have developed it as adults. By understanding how tissue can promote or increase the risk of metabolic diseases, Santosa’s research will help develop better treatment for obesity, from disease prevention to nutrition management.

Under Santosa’s supervision at the MON lab, Kerri Delaney is a PhD student who examines various regions of fat tissue on the body and compares them between different groups of people to see if there are disparities between or within each group.

“Type 2 diabetes is one of the fastest-growing diseases in Canada,” says Delaney. “Obesity is a direct risk factor for Type 2 diabetes and the rate of obesity has been on the rise for the past 50, 70 years. We’re a growing population and as we become more obese, we develop more metabolic diseases.”

What makes Delaney’s research unique is that she examines cells in three different parts of the body via fat tissue biopsies: from under the skin — known as subcutaneous fat tissue — from the stomach and from the thigh.

By comparing the fat cells in more than one area — between individuals going for bariatric surgery who may or may not have Type 2 diabetes — Delaney can see which area is worse. For example, people who have more stomach obesity tend to be more metabolically ill than people who have more leg obesity. Yet, at a cellular level, research has shown that there are additional differences at play. Delaney’s objective is to determine the independent effects of Type 2 diabetes and obesity on fat cells from different places in the body.

As with disease, when it comes to losing weight, some people have a harder time than others. Jessica Murphy, another PhD student under Santosa’s supervision at the MON lab, believes the answer might lie in the age at which obesity develops. Through her research, Murphy is trying to learn how that timing affects disease risk, by analyzing fat cells from people who have had obesity since childhood and comparing them with the cells of people who developed it later in life.

After identifying abnormalities between the two groups, Murphy wants to learn how each group responds to weight loss. In terms of fat-cell characteristics, she compares the differences between adult onset and childhood onset obesity and then puts individuals from each group on a weight-loss protocol of both diet and exercise.

“We guide them in terms of how to improve their nutrition and reduce their caloric intake by 20 per cent,” she says. The individuals in her study are also put on a cardio exercise program at the PERFORM Centre. Once they complete the full weight-loss protocol, Murphy conducts the fat biopsies and assessments once again to observe any differences. The goal is to get them to approximately 10-per-cent weight loss.

Murphy is intrigued by the results. “It’s exciting to see how these two groups of individuals do change after the program, as well as to see if there are improvements following their weight loss.”

Murphy hopes her research will improve comprehension of obesity and how it is treated. To date, she’s had more than 20 individuals complete her program. In order to yield more robust research results, her goal is to have 30 to 40 people complete both pre- and post-measures.

Health Canada’s overhaul of Canada’s Food Guide in early 2019 is a positive development, say staff and researchers at the PERFORM Centre’s Nutrition Suite.

The suite’s supervisor, Théa Demmers, a registered dietitian-nutritionist, says the new guide is an affirmation of what she and fellow colleagues have already endorsed: we should consider meals as a wellbalanced plate of colourful and dark green vegetables, fruits, whole grains and protein.

The latest version of Canada’s Food Guide supports a balanced plate of food, rather than suggesting a daily number of servings from four specific food groups, a recommendation that, until this year, had not been updated since 2007.

The idea of the balanced plate, according to Demmers, has existed in diabetes education since the 1990s.

“I think the new food guide really supports what is useful for people who are trying to plan their daily meals and meet their goals for both health and weight management, if necessary,” she says.

Through nutrition counselling and cooking workshops, Demmers helps advance research in the prevention of chronic diseases and helps promotes healthy habits. “I think the plate is visual, and seeing the proportions on it can be very positive and helpful for planning meals.”

While overweight and obesity statistics in Canada and around the world are worse than ever, Concordia’s PERFORM Centre researchers have high hopes for an improved understanding of how fat works. Through their research collaborations within the Concordia community and beyond, the intention is to develop knowledge in the field that will lead to more personalized treatments, and better prevention, education and weight-loss programs.