Extreme Dieting and Metabolic Adaptation: The “Biggest Loser” Dataset (Guest Post)

Let me start by stating that I am NOT a fan of the reality show, “The Biggest Loser”. The idea of sentencing obese people to 30 weeks’ hard labour and extreme food restriction under intense public scrutiny in the name of losing weight is basically torture for entertainment.

I saw some of them on a trip to southern Utah some years ago. While my husband and I were hiking in the magnificent desert of Snow Canyon State Park, these poor souls were marching along the road, heads down, sweating, panting, and really not having fun.

But was it worth it in the end? Did their strict 30-week regimen instill in them the discipline to maintain their now lean and mean bodies? Surely their metabolism had improved, and they were now fat-burning machines as a result of the 5 hour/day intense exercise.

A recent paper in the journal Obesity (Fothergill et al 2016 Persistent metabolic adaptation 6 years after “The Biggest Loser” competition”) addressed that very question. The authors conducted a very interesting study in which 14 of the 16 original “Biggest Losers” were recruited for follow-up studies on their metabolism and body composition. They had collected data from these subjects at three time points: before the competition, immediately after the competition, and 6 years after the competition.

Here are what I think are the most interesting findings of the study:

  1. While the subjects did regain weight, there was a mean weight loss of about 12% of body weight, and 8 out of the 14 participants in the study (57%) maintained at least 10% weight loss over the 6 years. That’s actually a pretty great outcome compared to most weight loss programs, where most people regain all of the weight within 1 year. 10% is really important, because some metabolic parameters can greatly improve after that kind of weight loss. In other words, it’s a very meaningful and significant weight loss outcome.
  2. The subjects maintained their high levels of physical activity. This is important, because….
  3. ….their Resting Metabolic Rates (RMRs) dramatically decreased at the end of the competition, and did not go back up, even after 6 years of maintaining their exercise regimen. This is called “metabolic adaptation”. The more weight the subjects lost, the slower their RMRs became.
  4. The most surprising finding was that metabolic adaptation did not correlate with weight regain. In other words, despite regaining weight, their RMRs remaining low, meaning that these subjects would probably have a low RMR permanently.
  5. Finally, the decrease in RMR did not correlate with changes in hormones and metabolites. Much has been made about changes in the circulating levels of the hormone Leptin. By the end of the competition, plasma leptin levels dropped dramatically (from 41 ng/ml to 3 ng/ml), but by 6 years, levels were up to 28 ng/ml; not quite normal, but it was increasing. Leptin is a hormone made by adipose tissue, and is secreted to tell the brain that the body has had enough to eat (what we call a “satiety signal”). Other metabolic hormones, such as thyroid hormone, did not change from baseline, and cholesterol levels did not change.

So, to summarize, these people did maintain some weight loss, but at the cost of their resting metabolic rate. Their metabolism has been permanently altered. Or, as Dr. Yoni Freedhoff says, destroyed. http://www.weightymatters.ca/2016/05/the-lasting-damage-of-biggest-loser_3.html

This study also showed that exercise does NOT have much impact on RMR. So all that exercise did not alter their body weights’ “set point” value.

However, these subjects clearly showed that they had a tremendous amount of discipline in maintaining their exercise regimen, probably because they were under intense public scrutiny. And most of them did maintain a 10% weight loss over the long term. So perhaps “biology is NOT destiny”, and a disciplined approach to lifestyle changes really can result in sustained weight loss.

So if exercise doesn’t increase RMR, what about diet? It was expected that the RMRs would reset back to their original values once the weight was regained, but that didn’t happen. So the lowering of RMR after that kind of dramatic weight loss is persistent, and may be permanent. The implications are that the subjects would have to eat far less than the recommended 2500 calories per day in order to maintain their original degree of weight loss. You’ve heard that some subjects had an “800 calorie handicap”, meaning that they would have to consume no more than 1700 calories per day just to maintain their weight loss. That would mean that these people would literally be hungry all the time. That is the direct result of a persistently damaged metabolism.

My take on this is that is it far, far better to simply exercise and get healthy and strong no matter what your weight. The scorched earth policy of The Biggest Loser will result in some weight loss, but at the cost of a permanently damaged metabolism.

savita (1)

Savita is a scientist and professor in London, Ontario. When she’s not in the lab investigating the causes of diabetes, she’s in the pool trying to keep up with her Masters swim teammates, or in a nice downtown restaurant enjoying local food and craft beer.

Ten Canadian Woman Health and Sports Pioneers You Should Know (Guest Post)

Some time ago, Sam posted a link to Ms. Fit Magazine’s “Ten Women’s Sport and Health Pioneers You Should Know”. While very informative, I commented that the list was very US-centric, and there are many Canadian women that followers of this blog should know. So I was invited to write a post about it! Here are my picks, and hopefully this will encourage others to seek out other Canadian women who have led the way in the arenas of health and physical activity.

Emily Howard Stowe, Physician. With no Canadian institution allowing women to study medicine, she studied in the United States and, in 1848, became the first Canadian woman to practice medicine in Canada. She was a founder of what is now Women’s College Hospital in Toronto in 1883. She was also founder and first president of the Dominion Women’s Enfranchisement Association in 1889.

Maud Leonora Menten, Biochemist. A dedicated and outstanding medical scientist, she was among the first Canadian women to receive a Doctor of Medicine degree at the University of Toronto, in 1911. She and colleague Leonora Michaelis developed the Michaelis-Menten equation, a concept that revolutionized how biochemical reactions are quantified. She also developed the alkaline phosphatase reaction still used in histochemistry, and performed the first electrophoretic separation of proteins. She also made several discoveries relating to regulation of blood sugar, the properties of hemoglobin and kidney functions. She authored over 100 scientific articles and was inducted into the Canadian Medical Hall of Fame in 1998.

Jessie Catherine Gray, Surgeon. A distinguished and internationally recognized surgeon, lecturer and researcher, Dr. Gray has so many “firsts” that “The Canadian Encyclopedia” calls her Canada’s First Lady of Surgery. From 1941 until retirement in 1965 she worked with the Women’s College Hospital in Toronto, as associate and as surgeon-in-chief. Here is the list of firsts: 1934, first woman gold medalist in medicine at the University of Toronto; 1939 first woman to hold a master of surgery degree; 1941 first woman resident surgeon a the Toronto General Hospital; 1941 first Canadian woman to become a “fellow” in the Royal College of Surgeons; first woman member of the Central Surgical Society of North America; 1966 first woman elected to the Science Council of Canada.

Ethlyn Trapp, Cancer researcher. She was BC’s first radiotherapist, and helped establish the BC Cancer Institute, and served as its Director from 1939-1944. She was the 1st woman president of the B.C. Medical Association in 1946/7 and in 1952 she was the 1st woman president of the National Cancer Institute of Canada. She was also president of the Federation of Canadian Medical Women. In 1963 she was awarded a citation from the Canadian Medical Association for her pioneering research in radiotherapy of cancer. She was inducted into the Order of Canada in 1968. The story of her family is detailed in “A Life Not Chosen: The Story of Ethlyn Trapp and Her Father.”

Sylvia Olga Fedoruk, Medical physicist. In the 1950s, she pioneered the development and use of Cobalt-60 for the curative treatment of cancer, and was instrumental in the development of a scanning device that could detect cancer using radioactive nuclides. She was the 1st woman trustee of the Society of Nuclear Medicine and in 1973 she was the 1st woman appointed to the Atomic Energy Control Board of Canada. She was also the 1st woman named to the position of Chancellor at the University of Saskatchewan, and 1st woman Lieutenant Governor of Saskatchewan. She was also an elite athlete, and is a member of Canada’s Curling Hall of Fame. She was appointed to the Order of Canada in 1986.

Barbara Ann Scott, Figure Skater. Scott is the first and only Canadian woman to win Olympic gold for singles figure skating, at the 1948 Winter Games. She is the only Canadian to have won the world, North American and European championships in one year, and the first to hold consecutive World championships. After retiring from figure skating, she became a distinguished horse trainer and equestrian rider, and founded and became chancellor of the International Academy of Merchandising and Design in Toronto. Scott has been inducted into the Canadian Olympic Hall of Fame, Canada’s Sports Hall of Fame, Skate Canada Hall of Fame and the International Women’s Sports Hall of Fame. She won the Lou Marsh Trophy as Canada’s Top Athlete in 1945, 1947 and 1948, and is an Officer of the Order of Canada.

Angela James, Hockey player. Dubbed the “Wayne Gretzky of women’s hockey”, Angela led Team Canada to 4 Women’s World Cup gold medals. In 2005, Hockey Canada honoured Angela with the Female Breakthrough Award, given for making significant contributions to the promotion and/or development of hockey for girls and women in Canada. Angela was inducted into both the Black Hockey and Sports Halls of Fame and the Ontario Colleges Athletic Association (OCAA) Hall of Fame in 2006. In 2008, she was one of three women inducted into the International Ice Hockey Federation (IIHF) Hall of Fame, the first in the Federation’s history, joined by Cammi Granato and Geraldine Heaney. Canada’s Sports Hall of Fame inducted James in 2009. In 2010, Angela James and Cammi Granto (USA) were the first women to be inducted into the Hockey Hall of Fame.

Nancy Greene, Alpine Skier. Nancy Greene was Canada’s top ski racer through the 1960’s, winning gold and silver medals at the 1968 Grenoble Olympics and overall World Cup titles in 1967 and 68. She won 17 Canadian Championship titles in all disciplines, and her 13 World Cup victories is still a Canadian record. In 1999, Nancy was named Canada’s Female Athlete of the Century. She has continued to contribute to the sport she loves through the establishment of the Nancy Greene Ski League, a grassroots program of Alpine Canada Alpin, which promotes ski racing for young Canadians.

Silken Laumann, Rower. Winner of 3 Olympic Medals and 1 World Championship in single sculls. In May 1992, just 10 weeks before the Barcelona Summer Olympic Games, Silken was injured in a brutal rowing accident that left her right leg shattered and useless. Twenty-seven days later, Silken was back rowing, and made the most remarkable comeback in Canadian sports history by winning the bronze medal for Canada in the Olympics. She has several awards that recognize her impact on women’s sport: BC’s Top 100 Women of Influence, the Canadian Association for Advancement for Women in Sport (CAAWS) “Most Influential Women in Sport”, and the Globe and Mail list of Most Influential Women in Canada. She is on the International Board for Right To Play, the Kid’s Champion for GoodLife Kids Foundation, and best-selling author of Child’s Play, all of which showcase her dedication and advocacy of children’s physical activity.

Clara Hughes, Cyclist/Speed Skater. Winner of 2 Olympic medals in cycling and 4 medals in speed skating. Clara is the only person, male or female, ever to have won multiple medals in both the Summer and Winter Olympic Games. Hughes was the first Canadian woman to win a medal in road cycling at the Olympics, winning two in the 1996 Atlanta Olympics, and is tied with Cindy Klassen in being Canada’s most decorated Olympian. Her list of awards include: Female Athlete of the Year by Speed Skating Canada in 2004; the International Olympic Committee‘s Sport and Community Trophy; and the 2006 List of Most Influential Women in Sport and Physical Activity by CAAWS. In 2010, she was inducted into Canada’s Sports Hall of Fame. She is also the National Spokesperson for the Bell Let’s Talk Mental Health initiative, and has started annual bike rides across Canada in order to raise awareness about mental health.

savita

Savita is a scientist and professor in London, Ontario. When she’s not in the lab investigating the causes of diabetes, she’s in the pool trying to keep up with her Masters swim teammates, or in a nice downtown restaurant enjoying local food and craft beer.