From The Times
June 6, 2009
How to stay trim for life
Diets fail because they work only over the short term. But this three-step guide by Dr Mark Porter will make sure that the weight you shed stays off
I have never been on a diet, but that is about to change — thanks to an argument with the waistband of my favourite shorts and new research suggesting that middle-aged spread increases the risk of frailty in old age — along with myriad other degenerative complaints.
At just over 14st (89kg) and 6ft 3in (1.9m) I don't have a serious weight issue — more an unsightly spare tyre — but that is not why I have never dieted. My main objection is that more than 20 years in the job have taught me that diets do not work. They may briefly help you to squeeze into your shorts or bikini, but you are almost certain to return to, or even exceed, your pre-diet weight.
Analyse all the research in this area and you are likely to come to the same conclusion — the only weight-management programmes that work in the long term involve lifelong change to diet and lifestyle, or stomach surgery. Anything else is doomed to long-term failure, explaining why so many of my overweight patients have shelves of diet books. If they worked they would need only one.
But profound long-term change is not going to get me into my shorts in time for our trip to Menorca — and gastric banding is going a tad too far — so I am going to follow the advice I give my patients. Physician heal thyself.
Step 1 is to work out where you are going wrong. The first thing I do when advising an overweight patient is to request a seven-day diary of everything he eats or drinks. This often reveals the problem, and patients can be surprised at how much they eat when they see it totted up. If it's not a quantity problem it's invariably quality.They eat the wrong types of food, typically high-fat or high-sugar, full of calories. NHS dieticians can provide more expert assessment and nutritional education.
Common problems with teenagers and older children include "hidden" calories in soft drinks, including juices — orange juice contains as much sugar as cola — which can account for 20 per cent of some children's intake.
And, while dieting is traditionally frowned upon during pregnancy, there is growing concern among doctors and midwives about the weight of would-be mothers — half of women are overweight before they conceive, and another third gain far more than they should during pregnancy, putting them at risk of complications ranging from miscarriage and diabetes to blood clots and premature labour. A food diary often reveals that they are eating for two. Most women probably don't need any extra calories for the first half of their pregnancy, and only 200 a day extra thereafter — the equivalent of only two slices of buttered toast.
Step 2 is to look to save somewhere between 250 and 500 calories a day, and calorie saving is what successful dieting is all about. If you consume less energy than you burn you will lose weight — it has nothing to do with whether you are an Atkins devotee, following a low-GI diet, or living on watermelon . Don't worry too much about your daily total, just try to reduce it through easy substitution, such as sweeteners in your tea and coffee, water instead of sugary soft drinks and fruit instead of confectionery and biscuits. A reduction of this sort should help you to shed about 2lb a week, the ideal rate of weight loss.
Calorie counting may have fallen out of favour — there isn't enough money in it for the diet industry — but it is important that people understand the concept because energy balance is critical to weight control. Requirements vary greatly depending on your age, size and daily activity. The following is a rough guide only — if you are active add 100 to 200 calories, if sedentary subtract 75 — and note how sharply calorific requirements fall as you get older.
An average 9st (58kg) woman requires about 2,100 calories a day between the ages of 18 and 35, 1,900 calories between the ages of 35 and 55, and 1,600 calories between the ages of 55 and 75. An average 12st (75kg) man needs about 3,100 calories between the ages of 18 and 35, 2,800 calories between the ages of 35 and 55, and 2,400 calories between 55 and 75.
The drop-off in the amount of energy we burn is on account of a combination of reduced activity and a lower basal metabolic rate — as we get older we lose muscle bulk and so burn less energy at rest — a combination that is responsible for middle-aged spread. If you want to stay trim as you head into your forties and fifties you will need to eat less and do more to maintain the status quo.
Step 3 is to boost your activity levels. Exercise is a common factor among successful dieters so be sure to include it in your weight-loss programme. Fat is the body's main energy store. Exercise promotes weight loss because it increases energy expenditure (burns calories), depleting those stores at a faster rate, assuming you don't eat more.
THREE FAT EXCUSES
It's my glands, doctor. No it's not. There are medical conditions that can predispose you to weight gain (including thyroid disease) but these are relatively unusual and the majority of people who are overweight simply eat too much and /or do too little.
My metabolism is slow. No it isn't. Studies have shown that overweight people often burn more calories than slim people simply by having to lug their extra bulk around, and they tend to have higher metabolic rates at rest, too. Or, to put it another way, a relatively active obese 20-year-old woman would probably need to consume a minimum of 3,500 calories a day just to maintain her weight — which is 1,300 more than a slim 20-year-old.
I eat like a church mouse. Research shows that overweight people tend to underestimate their daily calorific intake, sometimes by as much as 800 calories.