Sunday, June 21, 2015

Can fasting help you lose weight and live for longer?

New research suggests that fasting could slow down ageing and extend people's lives. What fasting diets are there - are are they a good idea?

Fasting is in fashion. The 5:2 diet is now so mainstream that several restaurants offer special 500-calorie, three-course menus making it easier for those on the plan to eat out, and everyone from Benedict Cumberbatch to Miranda Kerr has used it to keep in shape.
But the 5:2 is just the tip of the iceberg when it comes to intermittent fasting (IF) diets. There are all sorts of ratios and variants on core idea of dramatically restricting calories for a few days each week while eating normally on other days. And while this approach seems totally at odds with the traditional health advice we’ve always been given about eating balanced, regular meals, a growing number of scientists are saying IF diets can reduce our chances of developing some chronic diseases and may even add years our lives.
The most recent evidence comes from the University of South California, where researchers found that 34 people on a low-calorie, low-protein diet had a decrease in risk factors associated with chronic diseases such as cancer, heart disease and Type 2 diabetes.

This builds on a number of earlier findings that suggest fasting reduces blood pressure, increases cellular repair and metabolic rate, and protects against conditions such as dementia and Alzheimer’s. And while it is not be a step towards eternal life, a 2015 study at the University of Florida revealed that fasting on alternate days increased the gene related to anti-ageing in human cells.
Short periods of starvation effectively mimic the eating habits of our ancestors, who did not have access to grocery stores or food around the clock.
It’s not without its risks and downsides, though. Dietitians warn that skipping meals can cause dizziness, difficulties sleeping, dehydration and headaches. Others are concerned it reinforces poor eating habits. “These diets can encourage a ‘scrimp and splurge’ approach to eating,” says British nutritionist Julia Harding. “They don’t necessarily promote a good understanding of food. People need to make sure they’re eating nutritious, balanced meals on their ‘off days’ and think beyond calories.”
As fasting continues to win new fans, the array of variations is about as dizzying as a day on zero calories. So here’s a round up of the key ones to know about…

The Fasting Mimicking Diet (FMD)
In the latest take on fasting (and one of the few using human subjects), academics at University of Southern California have developed calorie-controlled plan that dieters follow for five days per month, eating what they like for the rest of the time. Consisting mainly of vegetable broths and herbal tea, the plan restricts calories to between one third and a half of normal intake (1,090 calories in day one then 725 calories for days two to five), which its creators claim makes it easier and safer than total fasting. The result? After three months participants had reduced biomarkers linked to ageing, diabetes, cancer and heart disease as well as cutting overall body fat.

The 5:2
The best known of the bunch, 5:2 means consuming just 500 calories (or 600 for men) two days each week. You can spend your calories on one big meal, two medium meals (recommended) or three small meals. A 2012 study suggested that the 5:2 model may help to lower the risk of certain obesity-related cancers, such as breast cancer.

The 4:3 - aka the Every Other Day Diet
An update on the 5:2, coming from the doctor whose clinical trials sparked the craze a couple of years ago. Fasts are instead done on alternate days each week, omitting breakfast on fast days.

Master Cleanse ingredients
Juice Fasts
Swapping solid food for fresh pressed fruit or vegetable juices for anything from one day to a fortnight. Some are evangelical about it as a detox and weight loss solution, though many dieticians point out the body doesn’t need any help getting rid of toxins and criticize the lack of fibre and protein it provides. One of the most controversial and extreme forms is Master Cleanse, where a mixture of lemon juice, maple syrup and cayenne pepper is drunk six to 12 times daily, sometimes with the addition of a laxative tea.

Day On / Day Off – aka the DODO Diet
This diet demands three (non-consecutive) days a week almost completely without food. The night before a fast day your dinner must be protein and vegetables, then on a fast day you don't eat at all until the evening when you have another protein and vegetable-based meal. Its inventor, nutritionist Drew Price, says cutting out calorie counting on fast days makes it easier to follow, and suggests dieters can expect results of up to 7lbs of weight loss in the first week and 1lb to 3lbs in subsequent weeks.

The 16:8 – aka the Wolverine Diet
So named because actor Hugh Jackman used it to get into shape for the eponymous 2013 film, it involves not eating for 16 hours a day – for example, from 8pm until noon the next day, or from 4pm until 8am the next day. Two healthy meals are eaten in the other eight hours.

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