Saturday, March 21, 2009

Diet: South Beach

South Beach Diet doc reveals latest in diet, exercise

south beach diet

The South Beach Diet developer says the answer to the low fat vs. low carb debate is simple carbohydrates, which should be avoided. (AP File Photo)


Dr. Arthur Agatston, cardiologist and South Beach Diet developer, talks about diet and exercise:

Q: In your newest book, "The South Beach Diet Supercharged," you write that "the diet debates are over." What do you mean?

A: The consensus is that we're beyond low-fat versus low-carb debates ... The answer is healthy carbs -- nutrient-dense, high-fiber, vegetables, whole fruits, whole grains; the good fats -- omega-3 fish oils, olive oil ... These principles are, I would say, set in stone.

Q: You also include exercise in "Supercharged" because you say there's new evidence about the best way to exercise. What is that?

A: The major thing is the benefits of interval exercise. ... The analogy we use is driving a car. Doing highway driving at a steady speed, you burn less gas than if you are starting and stopping and accelerating. ... Doing short bursts, from as little as 10-12 seconds to 30-second bursts of higher-intensity exercise, you get a lot more high-intensity exercise in than if you just sprinted, because (with sprinting) you'd get tired in no time.

It also appears that you get muscle adaptations where you burn more fat as well. And even given the same amount of total calorie burning, by doing episodes of high intensity, you burn more fat, you handle sugar and your insulin levels are improved.

Especially for everyone who's so busy, 20 minutes is totally adequate for the intervals. Q: What about so-called core exercises, like Pilates?

A: For the "Boomeritis" problems, core training is very important. Just sitting slumped over a computer all day affects our core muscles between the shoulders and the pelvis. With the classic gym, you can get very big muscles and go home and lift something and have your back go out because your core is weak.

Q: Is there a difference in the kind of fat that's burned in interval exercise?

A: A study from (a scientific journal) took a group of untrained women -- a control group, steady-state exercisers and women doing interval training -- and the interval trainers burned more belly fat than the steady-state exercisers or the control group. They improved insulin levels as well.

That does help you reduce the dangerous type of fat, the belly fat.

Q: How is belly fat different than other fat?

A: Belly fat is just metabolically different than other fat that accumulates under the skin. Belly fat surrounds the organs and accumulates in response to high insulin levels. It's the apple shape versus the pear shape.

Any exercise will help burn belly fat faster (than other fat).

Visceral fat goes down more easily. People with a pear shape ... have to do a lot more exercise than somebody with predominantly belly fat.

But, a person with belly fat will also gain weight back more quickly. These are the people who can yo-yo more easily than someone who is "fat and fit." Q: Are there other influences on how easily people gain or lose weight?

A: Different ethnic groups have different rates of what's called the "thrifty gene," which is the gene for storing fat and for insulin resistence. Northern Mexicans have a big dose of that gene.