PHOTOGRAPHY: THINKSTOCKWHICH CARBS BECOME FAT?
“There are two main groups of carbohydrates –
complex or nutritious carbohydrates, and simple
sugars,” explains dietitian Dr Trent Watson. Crudely,
simple sugars, or monosaccharides, in foods such
as white bread and chocolate, send blood sugar
soaring, simultaneously promoting a flood of fat-
storing hormone insulin. In the make-you-eat-less
stakes, they’re less satisfying than more fibrous or
complex carbs.
Conversely, complex carbs satisfy hunger for
prolonged periods thanks to the snail’s pace at which
the body processes them. Where with simple sugars,
glucose hits your blood suddenly, complex carbs
release more slowly.
“Complex carbohydrates have many, many sugars
linked together, which your body digests down to
glucose to burn,” says Dr Watson. The best sources,
he says, include wholegrain breads and cereals, fruits
and vegetables.
“Carbs should account for 40 to 60 per cent of your
total energy intake, depending on your activity level,”
says Dr Watson. “There’s no reason why we shouldn’t
eat carbohydrates with every meal as long as you’re
not eating too many of them. The best strategy is
to consume small, regular sources of carbohydrates
throughout your day. If you’ve got a consistent supply
of nutritious carbohydrates then they are available
whenever you need it for the mental and physical tasks
that come up.”
A third type of carbohydrate promises to increase
fat metabolism and curb calorie intake.
“Resistant starch is starch that reaches the bowel
undigested,” says Maria Packard, spokesperson for the
Dietitians Association of Australia (DAA).
Theory goes that resistant starch sources effectively
prevent the body from accessing certain parts of the
food until it’s too late to use the calories. While regular
carbs yield four calories per gram, resistant starches
yield two to three. Proponents also praise RS’ satiety
clout. In a University of Surrey study, people who
consumed resistant starch in one meal consumed
10 per cent fewer calories during the course of the
next day.
They may also have metabolic benefits. A study
conducted by the University of Colorado Health
Sciences Center found that people who consumed 5.4
per cent of their carbohydrate intake in the form of
resistant starch increased their fat metabolism by as
much as 20 to 25 per cent.
The Australian National Health and Medical Research
Council (NHMRC) led the world in setting a daily
recommendation for per-person resistant starch intake,
setting the bar at 20 grams (four bananas or six spuds).
But Dr Watson says the real question should
concentrate on differentiating other types of carbs.
“Obesity is the enemy, not carbs,” he says.
Ultimately, if calories in are fewer than or equal to
calories out, you shouldn’t gain body fat.Even in your fat cells, fat can be beneficial,
due to the miracle hormone leptin.
“Leptin isn’t your average hormone,”
explains Dr Lavie. “It ultimately influences
all other hormones and controls virtually
all the functions of the hypothalamus, in
the brain. The hypothalamus is where your
inner dinosaur lives; this ancient structure
that predates humans is responsible for your
body’s rhythmic activities and a vast array of
physiological functions from hunger to sex.”
“When fat cells start to fill up and expand,
they secrete leptin, which acts as your brake
at the table. Once the fat cells begin to shrink
as their contents are burned for energy, the
faucet is slowly turned off and less leptin gets
released. Eventually you’re able to feel hunger
again and the cycle starts all over.”
“The next time you put down your fork
and pull away from the dinner table, you can
bow to your leptin.”
Many obese people have very high levels
of leptin due to expanded fat cells but don’tseem to receive the same cues of fullness,
leading many experts to believe they may be
‘leptin resistant’.
In terms of types of fat, saturated fat
builds more fat and less muscle than
polyunsaturated fat according to new
research from Uppsala University, recently
published in the American journal Diabetes.
However, the calories in good fats such
as fish or nuts are the same as those in so-
called bad fats, says dietitian Julie Gilbert.
Exceeding your energy needs with salmon or
nuts will cause weight gain just as exceeding
it with butter will.
But, increasing omega-3 polyunsaturated
fat intake primarily with oily fish can help
burn more fat, regulate blood sugar and
insulin levels and keep hunger at bay, says
dietitian and metabolic expert Matt O’Neill.
“Shifting the balance away from unhealthy
saturated fats to more healthy unsaturated
fats will definitely enhance how the metabolic
chemicals in your body function.”» CONTINUED FROM PAGE 89