Why fluctuating weight may be the death of you
We all know crash diets don't work in the long-term - and now there's even more reason to ditch the yo-yo cycle forever, as research links putting on the pounds to serious heart problems. Lisa Salmon reports.
It's likely you'll put on weight over the festive season - and equally likely you'll struggle to lose it. But many people will still embark on New Year diets, possibly losing a bit of timber, and then putting it back on again, in the classic yo-yo fashion.
However, although such yo-yoing is very common, new research suggests it could also be dangerous.
A US study found women in the normal weight range who lost and regained weight had about a three-and-a-half times higher risk of sudden cardiac death - where the heart's electrical system abruptly stops working - than women whose weight remained stable.
Yo-yo dieting was also associated with a 66% increased risk of death from coronary heart disease, where blood vessels to the heart become blocked with fat, in the normal weight women.
The research, which studied more than 158,000 post-menopausal women over an 11.4-year period, didn't find an increase in either type of death among overweight or obese women who yo-yo dieted, otherwise known as weight cycling.
"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," said Dr Somwail Rasla, lead author of the study at Brown University.
The research didn't explain how yo-yo dieting might increase the risk of death, but Rasla suggests it could be connected to the possibility that, as people gain weight, cardiac risk factors, such as blood pressure and glucose levels, often increase, and the body eventually makes adjustments to compensate for the changes.
But when people yo-yo diet, the body may not have time to make those adjustments.
Another theory, developed after a trial using mice, suggests yo-yo dieting may have an impact on DNA. "We found that mice exposed to weight cycling behaviours ended up with damage to their DNA," notes Rasla.
However, if you're overweight, it's not wise to completely abandon diets either, as evidence shows that being overweight in mid-life also increases the risk of dying from both types of heart disease.
The best solution, therefore, has to be to embark upon a healthy diet which aims to achieve a steady, regular, small weight loss, rather than the rapid, major loss that a crash diet aims for.
Nutritionist Cassandra Barns points out that as well as negatively impacting physical health, crash diets followed by weight gain can affect mental health, leading to guilt and low self-esteem.
"This can result in an unhealthy relationship with food," she warns. "By cutting back on calories to extreme levels while yo-yo dieting, you can be at risk of malnourishment, and you may be more tempted to overindulge in the likes of alcohol when off your diet. Also, when our weight fluctuates regularly, we often diminish muscle mass, which is crucial for a high metabolic rate when resting."
YO-YO-PROOF TIPS FOR HEALTHY WEIGHT LOSS
Don’t starve yourself
If you miss meals or starve yourself, your body will think there’s a shortage of food and will slow down your metabolism and hold onto fat stores.
Skip fad diets
Fad diets, especially those that miss out whole food groups, may work temporarily but are difficult to maintain for more than a couple of weeks.
Never skip breakfast
Breakfast gets your metabolism going after a night’s sleep. But it’s important to choose healthy breakfast options, such as wholegrain cereals like porridge, or natural dairy products like yoghurt and eggs, and fruit.
Add protein to each meal
Protein slows down the rate at which the stomach processes food, and slows the passage of the carbohydrates with it, leaving you feeling fuller for longer.
Don’t eat on the run
Eating while rushing makes your digestive system less efficient. Make a point of sitting down and eating your food calmly.
Eat little and often
Keep blood sugar and energy levels stable by eating something every three hours.
Don’t cut out all fat
Fat is an essential part of the diet. Eat oily fish, nuts, seeds.