Many of us have tried fad diets and other methods such as rigorous exercise to lose weight fast in a matter of days so we can fit into our favorite pair of skinny jeans. However, a month later, we’re sucking in our stomach and struggling to button those jeans after gaining back all the weight.

A study presented at the American Heart Association's Scientific Sessions 2016 suggests weight cycling, popularly known as "yo-yo dieting" (a significant increase or decrease of body weight of generally 10 pounds or more occurring multiple times) is bad for your heart health.

"Weight cycling is an emerging global health concern associated with attempts of weight loss, but there have been inconsistent results about the health hazards for those who experience weight cycling behavior," said Dr. Somwail Rasla, a lead author and internal medicine resident at Memorial Hospital of Rhode Island, Alpert Medical School, Brown University, in Providence, Rhode Island, in a statement.

Previous research has found significant weight fluctuations, especially in normal weight individuals, pose a higher risk for heart disease, shortly after menopause. The researchers believed that the link between weight cycling and heart disease is due to endothelial cells, which are cells that line the blood vessels. When people gain and lose weight consistently, these cells become damaged, preventing blood from flowing freely. When blood flow to the heart becomes restricted, this can often lead to a heart attack and stroke.

In the new study, Rasla and her research team followed the outcome of over 153,000 postmenopausal women who self-reported their weights as either normal (with a body mass index less than 25), overweight (a BMI of 25 to 29.9), or obese (a BMI greater than 30). The participants also reported their adult weight histories by describing themselves as maintaining stable weight, steadily gaining weight, steadily losing weight, or weight cycling (if they had lost and regained 10 pounds or more). Weight gained and lost during pregnancy doesn’t count as weight cycling, according to Rasla.

There were a total of 2,526 coronary heart disease deaths and 83 sudden cardiac deaths throughout the study. These deaths were categorized based on the women's starting weights and their weight histories over time.

For overweight and obese women, weight cycling was not associated with the risk of heart disease-related deaths. However, normal weight women who confessed to weight cycling were 3.5 times more likely to have sudden cardiac death than women with stable weights. Moreover, yo-yo dieting was associated with a 66 percent increased risk of coronary heart disease deaths in normal weight women.

Women of normal weight are less likely to be intentionally losing weight than overweight women. This weight loss could be due to illness, therefore, weight cycling in this group could be shielding an underlying illness, which perhaps could be an illness that increases risk of heart disease.

Despite the effect of weight loss, these findings suggest yo-yo dieting is never a good idea because the person will experience fluctuations that affect the entire body, known as the “overshoot theory.” For example, gaining weight raises blood pressure, cholesterol, and body fat. When someone loses weight, these levels drop, but they do not return to a healthy baseline because the person’s “normal” state was overshot by weight gain. Inevitably, the person’s health will decline if they continue a repetitive up and down cycle.

Rasla’s research does have several limitations; it’s an observational study, meaning it only shows a link between weight cycling and heart problems, but it does not establish a causal relationship. This warrants further research to explain the mechanism behind the association. But, it doesn’t help that the statistics for yo-yo dieting are grim.

An estimated 80 percent of people who have lost weight regain all of it, or more, after just two years. In a 2007 study in the American Psychologist, researchers analyzed 31 long-term diet studies, and found about two-thirds of dieters regained more weight within four or five years than what they initially lost.

So, how do we lose weight for good?

The idea is to lose weight gradually. The Cleveland Clinic suggests we can control our weight by eating fewer calories and by burning up more calories than we need. This helps keep the weight off, and it’s healthier in the long run.

It’s important to adopt a positive attitude to have good weight loss results and weight management. A commitment to slowly adopting a healthier lifestyle can help reinforce weight loss goals.

A tip when it comes to yo-yo dieting: don’t do it.

Source: Rasla S et al. Garas M, Roberts MB et al. Risk of Sudden Cardiac Death and Coronary Heart Disease Mortality in Postmenopausal Women With History of Weight Cycling. American Heart Association's Scientific Sessions 2016.