Winning the weight loss race
EAT less, exercise more. It’s the age old prescription for losing weight by health professionals and trainers. But how much less food, and how much more exercise are needed?
Nutritionists and dietitians have debated and researched on food intake, exercise and how they tie into achieving weight loss – while magazines and the health and fitness industry have advocated from taking cabbage soup all day to a plate of steak five times a day.
Brunei is not exempt from the global trend of bulging waistlines - 60.6 per cent of Brunei’s population is overweight and obese according the 2011 National Health and Nutritional Status Survey, up 16 per cent from statistics compiled in 1997.
In an attempt to sift through the pile of information, The Brunei Times spoke to Hj Zakaria Hj Kamis, senior dietitian and head of Public Health Nutrition Unit at the Health Promotion Centre (HPC).
The role of calories
Food can be summed up as energy, the amount of which can be measured through calories.
According to Hj Zakaria, calories are derived through three macronutrients – carbohydrates, protein and fat. One gramme of protein and carbohydrate contains four calories while a gramme of fat contains nine.
Sugar as a form of carbohydrate also contains four calories per gramme. The fundamental rule of weight loss - consume less energy than you expend in a day.
How many calories expended daily are primarily based on height, age, gender, weight, activity level and muscle mass.
“Each individual has a basal metabolic rate (BMR) – which is how much calories one burns at complete rest. After BMR is determined, you factor in what your activity level is – on one end of the spectrum you have little to no exercise and on the other extreme you have daily strenuous exercise or physical activity.
“The higher your activity level, whether through a physical job, walking or through exercise, the higher your calorie expenditure for the day will be.”
A 75-kilogramme, 25-year-old male who is 165 centimetres tall and does little to no exercise will burn approximately 2,000 calories in a day, while a female of the same age standing at 155 centimetres and weighs 60kg burns 1,750 calories with minimal activity.
“If you burn 2,000 calories a day, and you consume that same amount – you will maintain your weight. For weight loss purposes you need to be lower than your expenditure, which is called a calorie deficit.”
How severe the deficit will determine the speed of the weight lost – but there are drawbacks with taking severe deficits, Hj Zakaria says; including low energy, bad mood and hunger, all of which will make the deficit difficult to maintain in the long run.
“At the HPC we advocate our clients target a five-10 per cent weight reduction, by reducing their calories by 300-500.
“In the case of someone expending 2,000 calories, eating 1,500 calories everyday will give you substantial weight loss if adhered to over a period of weeks and months,” he added.
Hj Zakaria advised being aware of portions as well as choosing food rich in vitamins and minerals.
“Vitamins and minerals (micronutrients) are different from macronutrients in the sense that they do not contain calories, but are absolutely essential for healthy bodily function.
“It’s possible to eat junk food and lose weight for as long as you are still within a calorie deficit – as reported in the media before, where people have lost weight only eating Mars bars or McDonalds – but these diets are usually severely lacking in micronutrients and fibre.”
Satiety (fullness) is another issue why people targeting weight loss should strive for plenty of vegetables and controlled amounts of fibrous fruit and complex carbohydrates.
“If you drink a can of Coke, you’ve already consumed 30 grammes of sugar and you are barely likely to feel full at all. Conversely, a large apple has or even whole head of broccoli has the same amount of calories, and will control your appetite by keeping you fuller for longer through the extra bulk (fibre) and weight.”
Dieters should take a closer look at the source of their carbohydrates. The glycemic index (GI) ranks carbohydrates according to how quickly they are absorbed by the body – resulting in how fast they raise blood sugar levels after eating.
“Choosing foods which are low to medium on the GI scale like vegetables, beans and certain fruits like banana and oranges will help control your blood sugar and help you gain control of your appetite.”
Hj Zakaria said portion control is necessary for foods that are considered “unhealthy” and higher on the glycemic index scale.
“Most people know that when dieting, you should limit food which is calorie dense and contains no micronutrients – many cakes and fast food fall under this category.
“But what people also need to realise is that portions absolutely matter. A little ‘junk’ is better than a lot. Watermelon for example is high on the glycemic index, but your blood sugar isn’t affected in the same way if by having a few slices of watermelon versus having 20 slices.”
To lose weight, HPC recommends that half of your plate consist of vegetables, with another quarter from a protein source and the remaining quarter from a carbohydrate source.
There are diets that advocate extreme caloric restriction - some only allowing liquids to be consumed, often referred to as juice fasts, cleanses or detoxes while others advocate the near-complete removal of food groups, such as the Atkins and ketogenic diet.
“People lose weight so quickly on these diets because the calories are low. If you are only taking juice or soup, it will not amount to a lot of calories.
“Most of society has 50 per cent of their calories from carbohydrates, so for those going on low-carb diets, they’ve effectively halved their total food intake for the day.”
“Fad and crash diets do not address the root problems of weight loss. They advocate extreme measures, and unless you can sustain them for the rest of your life, the evidence points to you regaining the weight lost.”
There is also evidence suggesting that crash dieting puts the body into ‘starvation-mode’ where the body, in an attempt to protect and preserve itself the face of very low levels of food, lowers metabolism and lead to weight gain when one returns to regular eating levels because the daily calorie expenditure is lower than before.
Future of weight loss
A five-10 per cent reduction in weight, recommended by health institutions worldwide, can be shown to bring significant health benefits.
“A lot of people have unrealistic expectations of how much weight loss they want to achieve and especially in the time period they expect to achieve it,” said Hj Zakaria.
“Scientists researching weight loss are now slowly moving away from searching for what works in the short term to examining what approaches can be taken towards weight loss that is sustainable and achievable by many over the long run.”
For those still debating whether calories matter – Hj Zakaria says the science is conclusive.
“The controversy of whether a calorie is a calorie will continue, but the research continues to point to the simple truth - how much energy (calories) you are consuming balanced against how much energy you expend - does matter.”
The Brunei Times