Posts Tagged ‘diet’

Combo Diet-Exercise Programs Trim Diabetes Risk

A combination of diet and physical activity programs offered in the community reduce the risk of type 2 diabetes in patients who are at increased risk, according to new federal data.

Programs Help Patients Revert to Normal Glycemic Levels

• Strong evidence suggests that a combination of diet and physical activity programs can reduce new-onset diabetes for persons at increased risk for type 2 diabetes.

• These programs also increase the likelihood of reversion to normal glycemic levels and improve diabetes and cardiovascular disease risk factors, including weight, blood glucose levels, blood pressure, and lipid levels.

• The US Community Preventive Services Task Force recommends the use of combined diet and physical activity promotion programs to reduce progression to type 2 diabetes in those at increased risk.

Combined Program’s Critical Components

• Critical components of a combined diet and physical activity program include trained providers in clinical or community settings who work directly with program participants for at least 3 months; some combination of counseling, coaching, and extended support; and multiple sessions related to diet and physical activity, delivered in person or by other methods.

• Programs also may use 1 or more of the following: diet counselors in various specialties (eg, nutritionists, dietitians, and diabetes educators); exercise counselors in various specialties (eg, physical educators, physiotherapists, and trainers); physicians, nurses, and trained laypersons; a range of intensity of counseling, with many or few sessions, longer- or shorter-duration sessions, and individual or group sessions; and individually tailored or generic diet or physical activity programs.

• Programs should include specific weight-loss or exercise goals and a period of maintenance sessions after the primary core period of the program.

US Task Force Conducts Systematic Review

• The task force recommendation is based on evidence from a systematic review of 53 studies that described 66 programs.

• Most programs used a combination of in-person individual and group sessions.

• Almost all programs led to weight loss, reduced risk of diabetes, or both.

• More intensive programs led to more weight loss and less development of diabetes.

Group Programs More Cost-effective

• These diet-exercise programs were cost-effective; group-based programs were the most cost-effective.

• Health care providers usually are the primary resource for patients at increased risk for type 2 diabetes.

• The task force suggests that health care providers keep informed about local prevention programs offered by community centers or run by insurers or nonprofit or other private contractors.

Take-home Message:

• A federal task force’s systematic review found combined diet and physical activity programs can help prevent or delay the development of diabetes.

Choosing the Diet that Will Work for You

Scores of weight-loss diets have been in the limelight over the years.

But relatively few have been carefully studied.

What do the data say about the effectiveness of diets and how can you use that information to choose a weight loss approach that will work for you?

In the February 7 issue of Healthbeat newsletter from Harvard Medical School, I was pleased to see the answer is that no one diet works for everyone.

You have to figure out the best eating plan for you.

“The take-home lesson is that it is okay to experiment on yourself,” states the newsletter.

“If you give a diet your best shot and it doesn’t work, maybe it wasn’t the right one for you, your metabolism, or your situation.

Don’t get too discouraged or beat yourself up because a diet that ‘worked for everybody’ didn’t pay off for you.

Try another.”

Here’s the newsletter’s take on the diet studies and what they mean.

The bottom line is you have to reduce the amount of calories you take in (and also burn off calories through exercise) to lose weight.

The diet studies

The reality is that when it comes to shedding pounds, the key is cutting calories — and it doesn’t really matter whether those calories come mainly from steak, bread, or vegetables.

A study led by Harvard researchers published in 2009 in The New England Journal of Medicine compared four different low-calorie diets (high fat, high protein; high fat, average protein; low fat, high protein; and low fat, average protein) in 811 overweight adults.

Although all the participants lost an average of about 13 pounds in the first six months (about 7% of their initial weight), they started to regain at the one-year mark.

After two years, average weight loss was the same in all groups.

An earlier study in The Journal of the American Medical Association suggested that it’s whether you stick with whatever diet you choose that makes the difference.

In this study, overweight and obese adults were assigned to follow the Atkins diet, the Ornish diet, Weight Watchers, or the “Zone” diet.

After one year, nearly half of the participants had dropped out of the study.

But those who didn’t lost similar amounts of weight (about 5 to 7 pounds each, on average).

People assigned to the Atkins and Ornish diets were more likely to drop out of the study, suggesting that many people found these plans too extreme.

But for certain people, the structure of a restricted plan may be helpful.

Experts advise people to keep the percentage of their calories from major nutrients within the recommended federal guidelines:

Protein: 10% to 35%
Carbohydrate: 45% to 65%
Fat: 20% to 35%

Note that diets that are less than 45% carbohydrate or more than 35% protein are hard to follow, and they’re no more effective than other diets.

In addition to possibly increasing the risk of heart disease, diets with very low carbohydrate levels may have a negative effect on mood, according to several studies.

Low-fat: Doesn’t taste great … and is less filling

Once the main strategy for losing weight, low-fat diets were shoved aside by the low-carb frenzy.

But healthy fats can actually promote weight loss, and some fats are good for the heart; eliminating them from the diet can cause problems.

Since fat contains 9 calories per gram while carbohydrates contain 4, you can theoretically double your food intake without taking in more calories by cutting back on fatty foods and eating more that are full of carbohydrates, especially water-rich fruits and vegetables.

Still, such a diet tends to be less filling and flavorful than other diets, which lessens its long-term appeal.

Low-carbohydrate: Quick weight loss but long-term safety questions

The low-carb eating strategy is based on the biological fact that eating carbohydrates raises blood sugar levels, which triggers an outpouring of insulin from the pancreas.

The theory goes a step further, claiming that high insulin levels produce hunger, so people who eat carbohydrates take in more calories and gain weight.

Low-carbohydrate diets tend to cause dehydration.

To make up for the lack of carbohydrates in the diet, the body mobilizes its own carbohydrate stores from liver and muscle tissue.

In the process, the body also mobilizes water, meaning that the pounds shed are water weight.

The result is rapid weight loss, but after a few months, weight loss tends to slow and reverse, just as happens with other diets.

The American Heart Association cautions people against the Atkins diet, because it is too high in saturated fat and protein, which can be hard on the heart, kidneys, and bones.

The lack of fruits and vegetables is also worrisome, because eating these foods tends to lower the risk of stroke, dementia, and certain cancers.

Most experts believe South Beach and other, less restrictive low-carbohydrate diets offer a more reasonable approach.

Mediterranean-style: Healthy fats and carbs with a big side of fruits and vegetables

Mediterranean-style diets emphasize good fats and “good” carbs.

Saturated fat, trans fat, and cholesterol are the bad guys.

Good fats are monounsaturated (found in olive oil, for example) and polyunsaturated (found in such foods as fish, canola oil, and walnuts).

Mediterranean diets tend to have a moderate amount of fat, but much of it comes from healthful monounsaturated fats and unsaturated omega-3 fats.

It is high in carbohydrates, but most of the carbs come from unrefined, fiber-rich foods.

It is also high in fruits and vegetables, nuts, seeds, and fish, with only modest amounts of meat and cheese.

People living in Mediterranean countries have a lower-than-expected rate of heart disease.

But the traditional lifestyle in the region also includes lots of physical activity, regular meal patterns, wine, and good social support.

It’s hard to know what relative role these different factors play — but there is growing evidence that in and of itself, the diet can reduce cardiovascular risk and the development of diabetes.

Six Ways to Control Your Weight

Healthy Weight Week (January 15 to 21) kicks off today to celebrate healthy diet-free living habits that last a lifetime and prevent weight problems.

Two-thirds of the American population is overweight or obese, and obesity numbers will continue to rise unless Americans stop eating more calories than they use, according to Brian Sharkey, a leading fitness researcher and author of Fitness Illustrated (Human Kinetics, 2011).

“In ages past, when the human food supply was unpredictable, people could not count on three square meals a day; as a result, the human body learned how to store energy in the form of fat,” Sharkey says.

“Today, most of us enjoy access to a dependable and plentiful food supply, but our bodies still store energy even though the need for doing so is gone.”

To lose weight, Sharkey says people often turn to restrictive diets, which can backfire and cause weight gain.

“When you diet, your body becomes more fuel efficient and your metabolic rate declines,” Sharkey explains.

“As a result, even more dieting or exercise is required in order to reduce excess weight.

During this cycle, your weight loss slows, and you regain weight three times faster.”

When a person is on a diet, the body uses protein for energy, which means a person can lose muscle protein with each dieting cycle.

As muscle is lost, the capacity to burn calories is reduced.

“Thus, each time you diet to lose weight, you lose lean tissue and must therefore decrease your caloric intake in order to avoid subsequent weight gain,” Sharkey adds.

“As a result, the only way to minimize the loss of lean tissue while dieting is to exercise.”

The safest way to lose weight and keep it off is to eat fewer calories and burn more with physical activity.

In Fitness Illustrated, Sharkey offers six keys to maintaining a healthy weight:

1. If you are active, consume 55 to 60 percent of each day’s calories in the form of complex carbohydrate (beans, brown rice, corn, potatoes, or whole-grain products) and fruit.

2. Limit your fat intake and avoid saturated fat and trans fat.

3. Eat a sufficient amount of lean, high-quality protein (15 percent of your daily caloric intake) to meet your protein needs during training.

4. Achieve weight control by balancing your caloric intake with your caloric expenditure.

5. Since metabolic rate declines with age, you will have to eat less, engage in more activity, or do both in order to maintain a healthy weight.

6. Remember that dieting often leads to future weight gain, especially when it is done without physical activity.