Consuming foods like soft white bread and jasmine rice lead to greater weight gain after weight loss, new research suggests. Such foods can also raise blood glucose levels, increasing the likelihood of type 2 diabetes.
High glycemic index (GI) versions of foods like bread, potato and rice (for example, soft white and brown breads, desiree potatoes and jasmine rice) are likely to significantly increase the risk of weight gain following weight loss, new research suggests.
“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.
Methodology
The researchers, led by Professor Anne Raben from Copenhagen University, used data from PREVIEW—their 2013 to 2018 global study of over 2,000 people classified as overweight or obese, who were at high risk of developing type 2 diabetes.
In the first phase of the study, all participants consumed meal replacement shakes to achieve fast weight loss, equivalent to at least eight percent of their body weight (about 11 kilograms) in eight weeks.
In the second phase, lasting three years, the 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. Despite their best efforts, all four groups regained some of the weight they’d lost.
But in the secondary analysis published this week, it was clear that the lower the GI of the diet, the smaller the weight regain. The beneficial effect of GI was still present after adjusting for differences in protein, fibre, and other factors.
The results were published in the prestigious journal Diabetes Care.
Beating the battle of the bulge
Professor Brand-Miller, from the University’s Charles Perkins Centre, said: “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.”
Kate Obermeyer’s husband, Ben, participated in the PREVIEW study. She said it had beneficial effects for her partner and her Sydney-based family.
“I didn’t realise that many of the foods we ate were low fibre and high GI—both of which can contribute to weight gain and pre-diabetes,” she said.
“My husband had a family history of diabetes, and I have a family history of heart disease. Though Ben was the study participant, we all followed the eating plan.”
According to the latest data, around one million Australians have Type 2 diabetes, and two million people are at high risk of developing the disease. The World Health Organization states that the global prevalence of diabetes is increasing. In 2019, it directly caused an estimated 1.5 million deaths.
About the Glycemic Index (GI)
All carbohydrate foods raise blood glucose levels in the hours after eating, but some have a faster and greater impact because they are digested faster. On a scale where glucose in solution has a score of 100, many varieties of bread, potatoes and rice have a high GI—in the range 70-100. But other foods, such as beans, pasta, and dairy products, have a lower GI (30-55).
As the rates of obesity and its associated metabolic diseases continue to rise globally, there is a pressing need to develop disease management strategies that are both effective and comprehensive. To combat obesity and its downstream metabolic consequences, many attempt to mitigate these effects through dieting interventions such as calorie restriction (CR) [1].
Calorie restriction (CR) has been the most widely practiced form of diet intervention, where the daily total caloric intake is reduced without malnutrition [2,3]. The benefits of CR on metabolism and cardiovascular health are well appreciated [4,5,6]. Unfortunately, the benefits from dieting are often unsustainable in the long term largely due to the termination of dieting regimens, referred to as post-dietary conditions hereafter [7].
Long-term adherence and compliance to CR is challenging and has been shown to create many post-dietary effects [4]. In the context of this review, we use a comprehensive definition of post-dietary effects that encapsulates body weight regain and loss of metabolic benefits. Weight regain is the quick repossession of body weight that was intentionally lost during a dieting intervention, and metabolic phenotypes include parameters such as insulin resistance, glucose tolerance and energy expenditure.
Post-dietary CR studies have reported weight regain and loss of metabolic benefits [4,5,6]. Despite the benefits of CR, long term commitment to this diet remains a challenge for many individuals [8,9]. Several clinical studies have reported high dropout rates or insufficient follow-up data due to difficulties of adherence to a CR regimen [10]. The constant episodic change in body weight, defined as weight cycling, can increase the risks of developing metabolic and cardiovascular diseases [11,12].
Due to CR’s compliance challenges, there has been a shift in interest towards intermittent fasting (IF) regimens, such as time-restricted feeding (TRF) and alternate-day fasting (ADF) [13,14].
IF interventions are defined by periodic cycling of fasting and feeding periods, which is deemed to be a more practical diet because it encompasses the freedom to be performed in the presence or absence of CR [15]. IF studies have indicated that even under an isocaloric state, subjects have improved insulin sensitivity, glucose tolerance, and improved response to oxidative stress [16].
Although these increasingly popular fasting regimens have shown beneficial effects in both pre-clinical and clinical studies [17,18,19,20,21], mechanisms underlying post-dietary weight regain and metabolic derangements are not well understood. CR studies in mouse models have suggested that post-dietary body weight regain and metabolic impairments are associated with mechanisms driven by the gut microbiome, hormonal changes, and adipose tissue biology (summarized in Figure 1).
Due to the current lack of post-dietary studies in the field of IF, a burning issue in this field is the lack of understanding regarding the post-dietary effects of IF. Therefore, in this article, we review and synthesize the lessons learned from post-dietary CR studies in rodents and humans to provide insight into the post-dietary mechanisms in order to predict the physiological response in IF post-dietary studies.
Schematic diagram summarizing the metabolic post-diet effects of CR and IF regimens in mouse and human studies. (Created with BioRender.com).
reference link : https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7909542/
More information: Ruixin Zhu et al, Dose-Dependent Associations of Dietary Glycemic Index, Glycemic Load, and Fiber With 3-Year Weight Loss Maintenance and Glycemic Status in a High-Risk Population: A Secondary Analysis of the Diabetes Prevention Study PREVIEW, Diabetes Care (2021). DOI: 10.2337/dc20-3092
