Nearly two out of three Americans are now considered overweight or obese. That’s why so many people make New Year’s resolutions to lose weight, become more active, and feel better. Among popular diets – Atkins and South Beach, Weight Watchers, Mediterranean, DASH, Sugar Busters, and many more – are any especially effective? Hard to say, there’s not enough evidence for a definitive judgment.
Calories Still Count
The basic principle and premise of any diet comes down to ‘calories in versus calories out, referring to how many calories you consume, how well your body burns up calories, and how active you are. Your metabolic rate can be also influenced by genetics.
Because diets like Atkins emphasize high protein and fat but sharply limit carbohydrates, some fear such regimens may be bad for the heart. However, some studies found that the low-carbohydrate diet surprisingly showed a greater improvement in some risk factors for coronary heart disease versus a low-fat diet, and it noted that the low-carbohydrate diet produced a greater weight loss by about 4% than did the low-fat diet – but only for the first six months. Then, after one year the differences were not significant any more. Other studies, however, found no evidence of an association between low-carbohydrate diets and increased cardiovascular risk, even when those diets were high in saturated fats.
Beware of High Glycemic Load
But, importantly, research shows that diets with a “high glycemic load” were 1.9 times more likely to promote heart disease. That refers to the amount and type of sugar in the diet. Both fats and carbohydrates are essential for health and should not be eliminated from the diet. But it depends on the type of fat and the type of carbohydrate. Excessive trans fats and sugars can add weight and carry health risks (e.g., heart disease, diabetes). Even worse, trans fats can also raise triglycerides and lower the level of the so-called good cholesterol, or the high-density lipoproteins (HDLs), while increasing the levels of the bad cholesterol, or LDLs, the low-density lipoproteins.
Vegetables and fruits have carbohydrates, and tend to have lower glycemic loads than sweets. The carbs in fruits, vegetables, and whole grain breads are complex carbohydrates. They take longer to metabolize, and they tend to raise blood sugar less rapidly after a meal and therefore are lower on the glycemic index. The simple sugars – like the kind found in cakes and candies – are digested quickly and tend to have a higher glycemic load.
Keeping the glycemic load under control is important, because the amount of carbohydrate consumed also affects blood sugar levels and insulin responses. In another study, those participants with the highest dietary glycemic loads not only gained more weight, they were also 37% more likely to develop type 2 diabetes over six years than women with the lowest dietary glycemic loads.
High dietary glycemic loads are also associated with increased triglyceride levels and decreased HDL cholesterol, both cardiovascular disease risk factors. To lower glycemic load, nutritionists recommend such strategies as:
- Increasing the amount of whole grains, nuts, legumes, fruits and non-starchy vegetable
- Reducing the amount of starchy high-glycemic index foods like potatoes, white rice and white bread
- Decreasing the consumption of sugary foods like cakes, candy, cookies and swetened drinks
Diet Drop-Outs
Many popular diets seem to work in the beginning because they are designed around a rapid weight loss, which is encouraging for the dieter. But typically, it is difficult to maintain the same rate of weight loss for long. Research shows that more than 50% of people who had tried a low-carbohydrate diet had given up within a few months.
One reason low-carbohydrate diets are successful for some people is they induce a feeling of satiety. When people add more whole grains, nuts, legumes, fruits and some vegetables into their diet along with protein, they tend to feel satisfied, and they actually eat less.
Another way to help control weight is to add more activity, which burns calories. It doesn’t have to be a vigorous workout, though. Move around more. Walk 20 or 30 minutes a day. Use the stairs instead of the elevator. Finally, anyone contemplating a weight-reducing diet consult his or her physician and possibly a dietitian for counseling to determine the best individualized dietary strategy.
