I worked this out all on my own a year ago… for me the logic is quite crude – people who starve lose weight. A great (but unfortunate) example is those who go on hunger strikes.
I needed to lose a few kilos. Just 10 or so – I had a minor pot belly but otherwise I am reasonably slim. I knew that the problem was lack of exercise and too many carbs. I tried removing carbs from my diet, but it was useless. I finally understood why people struggle to give up sugar or cigarettes. So I decided to just not eat. It was easy to begin with, I just chose the days when I was hungover. I already felt like crap, so some tummy rumblings on top wouldn’t matter much.
My diet evolved to where 2-4 mornings a week I just skipped breakfast. Once you get used to feeling hungry, it isn’t too bad. I would then eat a large-ish lunch and regular dinner.
The key: every hour that I feel hungry, my body is going to take that as a signal to burn fat for energy. For me that might only be 10-15 hours per week, but that was enough to lose the kilos at a rate of about one per fortnight.
Now, this was all just my only doing – no science, no diet guide. And I figure many people already do this (especially women who just have a ciggy and coffee instead of breakfast), but few would admit that sometimes they starve themselves.
Here’s the science, full article at i09:
…Most people associate fasting with juice cleanses or religious rituals — a torturous affair that lasts an entire day if not longer, and the sort of thing that should only be done a couple of times each year. But fasts can encompass any number of different strategies, including routines that simply limit the times when you eat each day, or on certain days of the week.
For example, there’s Alternate Day Fasting (ADF) and the Two Day Diet (also known as the 5:2 diet). We’ll get into these in just a bit, but what’s really starting to take off is dailyfasting — the practice of eating only during an 8-hour window of your choosing, and then fasting for the remaining 16 hours of the day.
While some might be inclined to cynically dismiss intermittent fasting as just another fad diet, the scientific evidence in support of daily fasting (or any fasting for that matter) is compelling. Restricting caloric intake for extended periods seems to do a remarkable job of staving off a number of health problems, while yielding some definite benefits.
…One hundred days later, the free-for-all group was a mess. They gained weight, developed high cholesterol, high blood glucose, and experienced liver damage and diminished motor control (ouch).
But as for the mice who practiced the intermittent fast, they weighed 28% less and showed no signs of adverse health. And what’s remarkable is that both groups ate the same amount of calories from the same fatty food. Not only that, the fasting mice also performed better on exercise tests — including a control group of mice who were eating normal food. (You can check out the study for yourself: “Extended Daily Fasting Overrides Harmful Effects of a High-Fat Diet: Study May Offer Drug-Free Intervention to Prevent Obesity and Diabetes“)
…It’s possible to extrapolate this to humans, too. Though anthropologists are not entirely sure how our paleolithic ancestors ate, it’s unlikely that they sat down for breakfast, lunch, and dinner. Those are eating routines from a more modern era — and even then, it’s likely that only the wealthy could afford multiple meals in one day. In all likelihood, our ancestors ate one or two big meals a day. And that was it. Consequently, their bodies were likely both adapted for and accustomed to going for extended periods without food during much of the day.
Other studies point to similar conclusions. Take the work of Valter Longo, for example. Longo, who works out of the University of Southern California’s Longevity Institute, has studied the effects of intermittent fasting on IGF-1, an insulin-like growth factor.
When we consume food, this hormone keeps our body in “go” mode, where our cells are driven to reproduce and facilitate growth. This is great when we need it, but not so much when we’re trying to keep off the weight. Moreover, while it’s good for growth, it can also speed up the aging process. And in fact, Longo compares the effect to “driving along with your foot hard on the accelerator pedal.”
Intermittent fasting, on the other hand, decreases the body’s expression of IGF-1. And it also appears to switch on a number of DNA repair genes. Restricted feeding, says Longo, makes our body go from “growth mode” to “repair mode.”
…Her evidence suggested that fasting can increase HDL-cholesterol (that’s the good kind), while lowering triacylglycerol concentrations. Fasting had no effect on blood pressure. She concluded her study by suggesting that fasting can modulate several risk factors that are known to bring about various chronic diseases.
other research shows that intermittent fasting can offer neuroprotective benefits. Studies on humans show that it can help with weight loss and reduce disease risk.
And incredibly, there may even be a link to cancer. Another study study by Varady and M. Hellerstein on mice indicated that both caloric restriction and alternate-day fasting can reduce cancer risk and reduce cell proliferation rates.
Short-term fasting can induce growth hormone secretion in men (which is a problem for guys after they hit 30), it reduces oxidative stress (fasting prevents oxidative damage to cellular proteins by decreasing the accumulation of oxidative radicals in the cell — what contributes to aging and disease onset), and it’s good for brain health, mental well-being, and clarity.
And as a study published just last week has shown, restricting calories can also lengthen telomeres — which has a protective effect on our DNA and genetic material, which in turn helps with cellular health (i.e. it helps us extend healthy lifespan).
And for people who wish to maintain a ketogenic diet — a metabolic state in which the body is in a perpetual state of fat burning instead of carbohydrate burning — intermittent fasting is a good way to help the body stay in ketosis