Michael Mosley is the author of the new diet book called "The
FastDiet." He is also starring in a PBS series that will air April 3.
(Photo: Rebecca McAlpin for USA TODAY)
The FastDiet: Lose Weight, Stay Healthy and Live Longer With the Simple
Secret of Intermittent Fasting (Atria Books, $24), by British physician
Michael Mosley and writer Mimi Spencer, is No. 46 on USA TODAY's
Best-Selling Books list. Mosley stars in an upcoming three-part PBS
series. The first part, Eat, Fast and Live Longer With Michael Mosley,
airs April 3.
The diet has a following in the United Kingdom, including some cardiovascular surgeons, TV journalists, chefs and celebrities.
But the book is generating a bit of controversy on this side of the
pond. Obesity experts in the USA say the diet may be hard for many
people to adhere to, and more research needs to be done to determine if
it's safe and effective. And one U.S. researcher doesn't like how her
work was used in the book to support the diet.
"I am a scientist at heart and I do not remotely claim that this is the
be-all and end-all," Mosley says. "It's just the beginning of something
interesting. People need to try it for themselves and see if it works."
Mosley, 55, who works for BBC as a medical journalist, says that when he
first read about the alleged benefits of intermittent fasting, he was
skeptical, too. "Nothing in my medical training had prepared me for
this," he says. Although most of the world's great religions advocate
fasting for faith purposes and some for health purposes, it seemed
drastic and difficult to him.
But then Mosley had some medical tests done and discovered he had some
risk factors for heart disease and diabetes, and he was a bit too heavy.
"My doctor recommended I go on medication for high blood sugar and high
cholesterol. She predicted that in 10 years I would be on eight
different medications. I decided I wanted to find a different way."
So he asked his boss at BBC if he could use himself as a "guinea pig" to
explore the science behind life extension, which focuses on calorie
restriction and fasting.
Based on his review of the research, he created what he calls the "5:2
diet." Five days a week, he eats normally; two days a week, he eats 600
calories. For women, he recommends 500 calories on the fasting days.
That would be about two poached eggs on a slice of whole-grain toast and
a bowl of raspberries for breakfast, and roast salmon with green beans
and cherry tomatoes for dinner.
Daily caloric needs vary depending on gender, age, height and physical
activity level. An older sedentary woman might need only 1,600 calories a
day to maintain her weight, while an active younger man might need
3,000.
Mosley divides his calories on the fasting days into two meals -
breakfast and lunch. "You can have it all in one meal if you fancy. I
found I was really quite irritable if I didn't have breakfast." He eats
300 calories at breakfast, often eggs with a bit of ham, and 300
calories for dinner - lots of vegetables and a lean protein. During the
day he drinks lots of fluids, such as water, tea and coffee.
If people eat 500 or 600 calories on the two fasting days each week and
don't significantly overeat on the "feed days" the rest of the week,
they will lose weight in a steady fashion, he says. Mosley didn't find
himself overeating on the feed days.
So what about feeling hungry? "I've gotten used to it. Hunger is one of those things that generally passes," Mosley says.
Where he used to grab sugary treats when he was hungry, he now snacks on
vegetables. "I crave vegetables because they're what I satisfy myself
with on a fasting day."
Some people worry that intermittent fasting will make them unable to
focus, he says. "What I've discovered is that it sharpens my senses and
my brain."
He thinks the plan may work for some people because it doesn't require
the deprivation that characterizes many diet plans. Dieters still get to
enjoy the foods they love, most of the time, he says.
Before he started intermittent fasting, Mosley, who is 5-foot-11,
weighed 187 pounds and had a body mass index of 26, which put him into
the overweight category. His waist was 36 inches; his neck, 17. His
fasting blood glucose (a measure of diabetes risk) was too high, along
with his cholesterol.
After two months on his program, he weighed 168 pounds, a loss of 19
pounds. He had a body mass index of 24, and his waist was 33 inches. His
neck size was 16. His cholesterol and blood glucose and other factors
fell to the normal range.
"I didn't want to lose any more because my wife, who is a doctor, said I
was looking gaunt. These days, I fast one day a week, and often skip
lunch on the other days."
One scientist who studies fasting takes exception to the way some of her
work was used in the book. "My research on alternate-day fasting has
been misrepresented in the book," says Krista Varady, an assistant
professor of nutrition at the University of Illinois-Chicago. "He is
using my research, which looks at fasting three to four days a week, to
support his diet, which encourages fasting two days a week."
But Mosley says he was partly inspired to try the 5:2 approach after
reading research done by Michelle Harvie, a dietitian in England who
wrote The 2-Day Diet.
U.S. obesity experts say Mosley's plan may work for some, but many questions remain.
"I am aware of only one randomized, controlled trial that compared
conventional daily calorie restriction with the 5:2 diet plan," says
Samuel Klein, director of the Center for Human Nutrition at the
Washington University School of Medicine in St. Louis. "In that
six-month trial, weight loss and most health benefits from weight loss
were the same in both groups.
"Additional and longer-term studies are needed to fully evaluate the
effectiveness of the 5:2 diet approach and to determine which people
might be more compliant with intermittent fasting than conventional
daily calorie restriction," he says.
Klein says the real question is this: "Is it easier for people to starve
two days a week than to reduce their calorie intake every day?"
"We do not know whether intermittent fasting has independent health
benefits beyond weight loss alone," he says. "In rodents, alternate-day
fasting has metabolic health benefits without a change in body weight,"
he says. However, alternative-day fasting in people causes weight loss,
so it's difficult to separate the benefits of intermittent fasting from
those of the weight loss itself, he says.
Tim Church, director of preventive medicine research at the Pennington
Biomedical Research Center in Baton Rouge, says, "We know that one diet
doesn't fit all. This style of caloric control may work for some people,
but we need more research to test the proposed mechanisms and
benefits."
The bigger question is whether people can stick with a fasting diet, given the amount of time and energy it takes, he says.
To learn about the science behind fasting, Mosley interviewed several
researchers, including ones with the National Institute on Aging and at
several major universities across the country. Much of the research on
fasting has been done on rats and mice, but there have been 11 human
trials on it, Mosley says.
Some of the medical benefits of fasting involve the hormone insulin-like
growth factor 1, called IGF-1, Mosley says. People need adequate levels
when they are young and growing, but high levels later in life appear
to lead to accelerated aging and cancer, including breast cancer and
prostate cancer, he says. Fasting appears to reduce the levels of IGF-1,
and it appears to switch on a number of repair genes. The reason it
happens is not fully understood, he says.
Mosley says fasting may also increase production of a brain-derived
neurotropic factor that seems to improve mood and protect the brain
against the ravages of dementia, Alzheimer's disease and age-related
mental decline. "This is based on animal research, and they are doing
human studies now."
Marji McCullough, a nutrition epidemiologist with the American Cancer
Society, says, "Higher levels of IGF-1 have been linked to several
cancers, including breast, prostate and colorectal cancer. Whether
reducing IGF-1 levels will lower cancer risk is plausible but not
proven."
The key for any diet is whether or not people can stick with it and keep the weight off, she says.
Mosley believes fasting has "undone" some of the damage he has done to
his body over the years and hopes that it will help him live longer and
healthier.
He recommends seeing your doctor before starting a fasting program. He
says fasting is not recommended for people who are pregnant, those who
are underweight, people with diabetes (especially type 1), and children
and teenagers who aren't fully grown. And he wouldn't recommend it to
people who have issues with food, although "there is no evidence it will
trigger anorexia or bulimia," Mosley says.
Although plenty of people have reported their weight-loss success
stories to him, not everyone is going to get the results they want,
Mosley says. "No diet is going to agree with everyone. Some people find
that they don't lose weight as fast as they thought. That's probably
from overeating on the other five days. It's not magic."
SOURCE : http://www.wltx.com/news/watercooler/article/228205/363/FastDiet-Book-Is-Attracting-Dieters-and-Doubters