There’s a lot more to losing weight than just calories in & calories out

You have to keep pushing yourself to get the benefit of the exercise as you get fitter.  That’s the message  in The Sydney Morning’s article called The Diet Dilemma.  You might think weight loss is simply about  kilojoules in/kilojoules out but there is a lot more to weight loss and health professionals it appears have been getting it wrong for years.
Keep pushing yourself ... you won't weigh less if you eat less.
Keep pushing yourself … you won’t weigh less if you eat less.

Eat less, weigh less. Simple? Not quite, writes Nick Galvin.

Losing weight is simple in principle. The rule of thumb has been that if you cut out 2100 kilojoules a day – the equivalent of two large lattes or a blueberry muffin – you will lose about half a kilo a week until you reach that magic number on the scales.

Simple – but, as it turns out, probably way too simple.

It now appears that dietitians, doctors and others may have been getting it wrong all these years. There’s a lot more to losing weight than just kilojoules in/kilojoules out.

Losing weight ... juist reducing your food intake is not enough.Losing weight … just reducing your food intake is not enough.

When you start to lose weight, your body slows down your metabolism. In other words, you use less energy for the same activities.

This reaction has its roots in our primitive past, says Professor Michael Cowley, director of the Monash Obesity & Diabetes Institute. “If you go on a diet, your body says, ‘Aha, here is a famine’, and it decreases energy expenditure, so you need less energy just to stay at that weight,” he says. “This is probably because we evolved in conditions where famine was frequent, and if you had an appropriate physiological response to famine, you were more likely to survive and your genes got propagated.”

The result is that if you stay on the same reduced-kilojoule diet, over time the gap between kilojoules in and kilojoules out narrows. In a paper published last year in The Lancet, researchers from the US National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) found that for a given weight-loss goal, half the loss would occur in the first year, but the remaining kilos would take another two years to lose.

Battling the bulge ... there's a lot more to losing weight than just kilojoules in/kilojoules out.Battling the bulge … there’s a lot more to losing weight than just kilojoules in/kilojoules out.

“The duration of diet you need to achieve meaningful weight loss is much longer than we used to think because there is a law of diminishing returns,” says Cowley. “If you are only decreasing food intake, it will take a lot longer for that weight loss to occur because your body fights against it.”

All this goes a long way towards explaining why so many dieters shed the first few kilos easily, then get discouraged because it gets harder to lose the rest of the weight (and then hit the nearest bag of chips out of frustration).

The NIDDK researchers also produced an online calculator that shows how many kilojoules you need to consume to lose a given amount of weight and how much you need to reduce your intake for good to maintain that goal weight.

The good news, however, is that it is possible to trick the body and override that primitive instinct to slow your metabolism in times of “famine”. You guessed it: exercise.

The National Weight Control Registry is an American research project that tracks people who have lost a significant amount of weight (at least 30 pounds, or 13.6 kilograms) and, critically, kept it off for at least a year.

Researchers are interested in what these successful slimmers have done to keep the weight off. One common tactic is sticking to a regimented diet, but another, says Cowley, is that they “exercise like crazy” for more than an hour a day. “We think this is how they are dealing with the fact that although their body wants to decrease energy expenditure, they are forcing it to [burn energy] by running on the spot or whatever.”

Exercise physiologist John Felton, from The Exercise Clinic in Sydney’s Crows Nest, says that, as well as prescribing an exercise plan, one of the things he focuses on are the “activities of daily living”.

It is all too easy for people simply to stop moving enough. “If you are in a sedentary job or you have got yourself into a sedentary ‘hole’ – you come home in the afternoon and sit down and watch television – that sedentary life becomes self-fulfilling,” says Felton. In essence, the less you move, the more difficult moving becomes.

Felton has clients wear an accelerometer for a week. The device monitors movement, from waking to going to bed, detecting spikes of energy and periods of inactivity. Incidental exercise can be as simple as doing the ironing or walking to a printer on the other side of the office.

“It doesn’t have to be a lot of exercise as long as it keeps people moving during the day to cut down those big periods of sitting,” he says. “It’s very easy to double the amount of energy expenditure with those daily activities if you start off at a low level.”

Another element, however, also contributes to the “plateau” effect in weight loss. Even as we get fitter, we often keep exercising at the same intensity rather than upping the effort and employing a training principle known as “progressive overload”.

“A lot of time that is not adhered to,” says Felton. “People will do their 40-minute or hour walk, and instead of looking for hills or aiming to maintain a heart rate, they do the same thing. If they maintain the same pace as they get fitter, their efficiency will improve and their heart rate will drop, so they will burn less energy as they do it.”

In other words, you have to keep pushing yourself to get the benefit of the exercise as you get fitter.

And stay away from the muffins.

Read more: http://www.smh.com.au/lifestyle/diet-and-fitness/the-diet-dilemma-20120603-1zplz.html#ixzz1widDocer
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