The study, which was published in the journal Circulation, was conducted by researchers from the Catholic University of Korea.
Yo-yo weight loss, also called weight cycling, increases your risk of suffering from heart attack, stroke, and early death, warned the researchers.
For their study, they tried to measure the full effect of weight cycling on the body by analyzing the data of 6,748,773 individuals from the Korean National Health Insurance system. Those individuals were generally healthy, and at the start of the study, none of them had diabetes, elevated blood pressure, or high cholesterol levels. None also had any previous heart attacks.
The researchers tracked the volunteers’ weight, blood pressure, blood sugar, and cholesterol levels from 2005 to 2012. When the study concluded, 54,785 of the patients had died, 22,498 had a stroke, and 21,452 had a heart attack.
Out of all the patients, those whose weight, blood pressure, blood sugar levels, and cholesterol levels fluctuated were 127 percent more likely to die, 43 percent more likely to suffer from a heart attack, and 41 percent more likely to have a stroke.
The researchers noted that since the study was observational, they were unable to provide an explanation as to why the fluctuations in the volunteers' measurements increased their risk of having heart attacks and strokes.
But why weight cycling negatively affects your body can be explained.
Some dietitians believe that sudden weight loss followed by weight gain may put a lot of stress on your body. (Related: Sure, being overweight is bad for your health — but so is yo-yo dieting.)
When you follow a restrictive diet, your body only receives a fraction of the calories that it needs. This makes it work hard to burn fat and muscle mass for energy. Because of this added stress, your body experiences elevated levels of inflammation and the hormone cortisol.
Cortisol is involved in stress and your body’s fight-or-flight response. Matt Edwards, a registered dietitian and a director of dietetics and nutritional science at GenoPalate, explained that cortisol is the body's "alarm system."
When the body is in danger, your cortisol levels rise. It's been confirmed that the long-term elevation of cortisol is linked to weight gain and increased anxiety or depression. Cortisol buildup can also increase your blood pressure, cholesterol, and triglyceride levels.
Edwards noted that the persistent fluctuations in cortisol associated with weight cycling could contribute to the root cause of heart disease.
Instead of alternating between harmful crash diets to lose weight fast and then binge eating, dietitians recommend a more long-term, healthful approach to weight loss that can also improve your overall health.
Dr. Nicole Harkin, a board-certified cardiologist and lipidologist from Manhattan Cardiovascular Associates, explained that while continued research is needed, a growing body of evidence suggests yo-yo dieting is harmful to your health.
But this doesn't mean people who are overweight or obese should stop trying to lose weight. Instead, Harkin advised that those who want to lose weight should follow a healthy diet that they can maintain.
If you want to lose weight, try a plant-based diet like the Dietary Approaches to Stop Hypertension (DASH) or the Mediterranean diet. Studies suggest that a plant-based diet is the healthiest way to maintain a healthy body weight and reduce the risk of cardiovascular disease.
Don't risk your cardiovascular health just to lose a couple of pounds easily. Try to manage your weight by following these effective, long-term weight loss habits.
To lose weight effectively, health experts highlight the importance of having healthy, long-term lifestyle habits instead of yo-yo dieting.
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