Women of normal weight who frequently yo-yo diet are three and a half times more likely to have a sudden cardiac death, a new study reveals.

Yo-yo dieting or weight cycling has dangerous effects on health — and especially the heart — whether you are normal weight or not.

7% of men and 10% of women are classified as severe weight cyclers (yo-yo dieters).

It means knowingly losing at least 5kg and regaining it at least three different times.

Now a study reports that older women of normal weight who yo-yo dieted for years are more likely to die from heart disease .

Dr Somwail Rasla, the study’s lead author, said:

“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 behaviour.”

The study looked at data from nearly 160,000 postmenopausal women over 11.4 years.

During 11 years follow-up, the researchers found:

• Those with normal weight at the start of the study, but whose weight had fluctuated were three and half times more likely to have sudden cardiac death compared to participants whose weight was stable.
• Risk of heart disease-related death was increased by a 66% in normal weight women who yo-yo dieted.
• Overweight or obese women who experienced weight cycling didn’t show any increase in any kind of death.
• Death rate didn’t increase in participants who lost weight without gaining it back or who put weight on but didn’t lose it.

The study hints that being overweight  in mid life raises the risk of dying from two types of heart disease.

The first one is coronary heart disease where blood vessels are blocked by fat and cholesterol, so reducing blood flow to the heart.

The second type is sudden cardiac death where the heart’s electrical system all of a sudden stops working.

Dr Rasal explained:

“Normal-weight women who said ‘yes’ to weight cycling when they were younger had an increased risk of sudden cardiac death and increased risk of coronary heart disease, which can lead to heart attacks and other serious issues.

The frequency of weight cycling — how often the women had lost and regained 10 pounds or more — was also a risk factor.

The more cycling, the more hazardous (to their hearts).”

The research was presented at the American Heart Association’s Scientific Sessions 2016.

 Yo-yo effect image from Shutterstock