The Fast Diet, a how-to diet book by Dr. Michael Mosley asks one question: “is it possible to eat normally, five days a week, and become slimmer and healthier as a result?”
His answer is yes.
After a checkup at his doctor’s office, Mosley was stunned—as a doctor himself—at the terrible results. Slightly over-weight, high cholesterol, and heading towards diabetes, Dr. Mosley realized it was time for change. He tried a calorie restriction diet, but this was too strict of a lifestyle to follow. Soon after, he was introduced to Intermittent Fasting, and this caught his attention.
Experimenting and modifying previous forms of intermittent fasting, Dr. Mosley created his own approach to a healthy diet. For him this didn’t mean eliminating food, but rather reducing one’s calorie intake for two non-consecutive days per week, which he calls the 5:2 approach. This revolutionary diet helped Dr. Mosley not only lose weight, but also gain overall improved health and fitness. His followers have reported tremendous improvements in health since beginning the Fast Diet, and science suggests eating this way supports anti-aging benefits.
So what does the diet exactly entail and how does it work?
Two non-consecutive days a week simply cut your calorie intake to 500 calories/day (females) or 600 calories/day (males). On non-fasting days, eat what you want—really!
As Dr. Mosley says, “counterintuitive as it may seem, no foods are off-limits, none forbidden. On the five days a week when we’re not restricting calories, we both eat freely—fish and chips, roast potatoes, cookies, cake. The Illinois study certainly found that volunteers encouraged to eat lasagna, pizza, and fries, during ‘off days’ still lost weight.”
Why does this work?
For longevity. This type of mild fasting works by signaling to the body that you are in a state of famine. When eating regular amounts of food, the body is focused on growth and only growth—not repair. When the body thinks you are enduring famine, instead of putting energy towards growth, a high energy job, it works instead on repairing the body—focusing to make the body stronger to withstand the ‘famine.’
One example of such repair is called Autophagy, where the body “breaks down and recycles old and tired cells.” Eliminating old, non-functioning cells is a key step towards anti-aging, and one that simply does not happen enough when eating at full capacity every day of the week.
For weight loss. The above explains how fasting works for longevity, but fasting has also proved to aid weight loss as well. Not only is it a reduction in calories (keep in mind you cannot over-eat on non-fasting days to make up for them!), but weight loss occurs through fasting due to changes in insulin levels.
When you eat, insulin levels are raised. High insulin levels signal to your body to go into fat-storage mode, which is necessary—but not always necessary. Insulin levels stay high for a few hours after eating, so if you are consistently eating throughout the day, or even eating three square meals a few hours apart, you are ALMOST ALWAYS in fat-storage mode; not the mode to be in when you are trying to shed some pounds! When insulin levels are lower due to lack of eating, the body goes into fat-burning mode…and that’s what we like to hear!
Dr. Mosley’s book describes in detail the processes that fasting triggers in the body and includes specific tips, meal plans, and documents both his and his co-writer Mimi Spencer’s journey into the world of the 2 day fast. The scientific studies and research he provides to back his claims are fascinating and offer a new perspective to the body and how exactly it reacts to what we put in it and when. With this new knowledge, Dr. Mosley crafts a manageable and straight forward plan to a leaner and healthier you.