Gained weight after losing it? High GI diet associated with 'weight gain creep'

woman gained eight
If you've noticed the kilos creeping back on, these foods may be to blame. Photo credit: Getty Images.

If you've lost a lot of weight, you'll know one of the hardest things is maintaining the loss once you've hit your goal weight. 

A new study published this week in journal Diabetes Care has shown it may be the types of foods we're eating that can lead to the kilos starting to creep back on.

High glycemic index (GI) foods are carbohydrate-based foods that are broken down quickly by your body and cause a rapid increase in blood glucose. 

Eating high GI versions of foods, like soft white and brown bread, potatoes and rice are likely to significantly increase the risk of weight gain following weight loss, the new research suggests.

The weights of over 2000 people classed as 'overweight or obese' were tracked from 2013 to 2018, with all participants given weight loss shakes to achieve fast weight loss at the beginning of the study. 

In the second, three-year-long phase of the study, researchers compared two diets and two exercise strategies: A high protein-low GI diet, or a moderate protein-moderate GI diet, each combined with either high or moderate-intensity exercise. 

The results showed the lower the GI of the diet, the smaller the weight regain. The beneficial effect of low-GI was still present after adjusting for differences in protein, fibre, and other factors.

"Weight regain is a common problem after rapid weight loss," said study co-author and University of Sydney professor Dr Jennie Brand-Miller.

"Prior to this research, there were few large-scale studies on long-term weight loss management and glycemic status. In the new research, as well as better weight control, low GI diets were linked to improved blood glucose levels.

"Maintaining lower blood glucose levels lowers the risk of developing type 2 diabetes, hardening of the arteries and inflammatory conditions such as arthritis.

Dr Brand-Miller says now they've discovered the link between a high GI diet and weight regain, they'll be researching how best to achieve a lower GI diet. 

"I think all of us have experienced weight gain creep over our adult life, and many of us have tried all manner of diets only to regain over time. 

"This new study tells us that choosing low GI versions of breads, potatoes and rice will make it easier to beat the battle of the bulge."