Study urges people to think twice before going on a diet

Plant-based low-carbohydrate diet linked with lower risk of premature death for people with type 2 diabetes
Plant-based low-carbohydrate diet linked with lower risk of premature death for people with type 2 diabetes

A new qualitative study highlights the negative interpersonal and psychological consequences associated with “yo-yo dieting,” also known as weight cycling. The work underscores how toxic yo-yo dieting can be and how difficult it can be for people to break the cycle.

“Yo-yo dieting – unintentionally gaining weight and dieting to lose weight only to gain it back and restart the cycle – is a prevalent part of American culture, with fad diets and lose-weight-quick plans or drugs normalized as people pursue beauty ideals,” says Lynsey Romo, corresponding author of a paper on the study and an associate professor of communication at North Carolina State University.

“Based on what we learned through this study, as well as the existing research, we recommend that most people avoid dieting, unless it is medically necessary. Our study also offers insights into how people can combat insidious aspects of weight cycling and challenge the cycle.”

For the study, researchers conducted in-depth interviews with 36 adults – 13 men and 23 women – who had experienced weight cycling where they lost and regained more than 11 pounds. The goal was to learn more about why and how people entered the yo-yo dieting cycle and how, if at all, they were able to get out of it.

All the study participants reported wanting to lose weight due to social stigma related to their weight, and/or because they were comparing their weight to that of celebrities or peers.

“Overwhelmingly, participants did not start dieting for health reasons, but because they felt social pressure to lose weight,” Romo says.

The study participants also reported engaging in a variety of weight-loss strategies, which resulted in initial weight loss, but eventual regain.

Regaining the weight led people to feel shame and further internalize stigma associated with weight – leaving study participants feeling worse about themselves than they did before they began dieting. This, in turn, often led people to engage in increasingly extreme behaviors to try to lose weight again.

“For instance, many participants engaged in disordered weight management behaviors, such as binge or emotional eating, restricting food and calories, memorizing calorie counts, being stressed about what they were eating and the number on the scale, falling back on quick fixes (such as low-carb diets or diet drugs), overexercising, and avoiding social events with food to drop pounds fast,” says Romo. “Inevitably, these diet behaviors became unsustainable, and participants regained weight, often more than they had initially lost.”

“Almost all of the study participants became obsessed with their weight,” says Katelin Mueller, co-author of the study and graduate student at NC State. “Weight loss became a focal point for their lives, to the point that it distracted them from spending time with friends, family, and colleagues and reducing weight-gain temptations such as drinking and overeating.”

“Participants referred to the experience as an addiction or a vicious cycle,” Romo says. “Individuals who were able to understand and address their toxic dieting behaviors were more successful at breaking the cycle. Strategies people used to combat these toxic behaviors included focusing on their health rather than the number on the scale, as well as exercising for fun, rather than counting the number of calories they burned.

“Participants who were more successful at challenging the cycle were also able to embrace healthy eating behaviors – such as eating a varied diet and eating when they were hungry – rather than treating eating as something that needs to be closely monitored, controlled or punished.”

However, the researchers found the vast majority of study participants stuck in the cycle.

“The combination of ingrained thought patterns, societal expectations, toxic diet culture, and pervasive weight stigma make it difficult for people to completely exit the cycle, even when they really want to,” Romo says.

“Ultimately, this study tells us that weight cycling is a negative practice that can cause people real harm,” Romo says. “Our findings suggest that it can be damaging for people to begin dieting unless it is medically necessary. Dieting to meet some perceived societal standard inadvertently set participants up for years of shame, body dissatisfaction, unhappiness, stress, social comparisons, and weight-related preoccupation. Once a diet has begun, it is very difficult for many people to avoid a lifelong struggle with their weight.”

The paper, “A Qualitative Model of Weight Cycling,” is published in the journal Qualitative Health Research. The paper was co-authored by Sydney Earl, a Ph.D. student at NC State; and by Mary Obiol, an undergraduate at NC State.

Are you at risk for diet-related disease? Where you spend your day plays a role

A USC and MIT led research team finds smartphone mobility data to be a good predictor of diet and diet-related disease
A USC and MIT-led research team finds smartphone mobility data to be a good predictor of diet and diet-related disease.

How many fast-food joints do you come across throughout your day and what does that have to do with your health? A lot, says Abigail Horn.

Horn led a multidisciplinary team that set out to ascertain whether smartphone mobility (i.e., location) data could provide a way to measure people’s individually-experienced dynamic food environments, at scale across large and diverse populations and diverse physical environments.

Horn explained, “Can we use mobility data to measure people’s visits to food outlets? Because that’s a good proxy for eating food at that outlet. And then, can we go further to see whether visits to food outlets observed in the mobility data predict people’s dietary disease rates?” 

Location, Location, Location 

“It’s well established that the physical environment can impact people’s eating decisions and therefore their diet-related health outcomes, but what we don’t know is the extent to which that is true,” said Horn

Physical food environments are the actual spaces where people acquire food. “The food outlets in their neighborhood, or around their workplace, or any location along their daily path. Things like grocery stores, restaurants, or corner markets,” explained Horn. 

These environments have been shown to impact people’s diets and therefore health outcomes – including diet-related diseases – in several ways. First, said Horn, “When people have low physical access to healthy foods, that can induce unhealthy choices out of convenience or necessity.” And second, “People can be cued by food environments. So, for example, if throughout your day you’re seeing fast-food outlets over and over again, that can cue or trigger certain behaviors” (i.e., eating more fast food). 

There are a number of studies looking at people’s home neighborhood food environments and associating these with food choices and diet-related diseases. But the findings have been mixed, as have the results of public health initiatives that have focused on home neighborhood food environments. 

Horn explained, “In the last decade or so, over a billion dollars have been invested in public health interventions in home food environments. This could mean building a grocery store in a food desert [a home neighborhood with limited access to nutritious food] or stocking the corner stores in that neighborhood with fresh fruit and vegetables.” But, she continued, “There’s been no measurable impact in increasing people’s healthy food purchases or health outcomes. So what’s going on here?” 

Kayla de la Haye is one of the members of the research team who could help answer that question. De la Haye is the Director of the Institute for Food System Equity at USC Dornsife Center for Economic Research, and has a background in public health, nutrition, and psychology. “One of my roles in this research was to bring expertise in how people make decisions about what to eat, and the consequences of food environments that inundate people with unhealthy options and put them at risk for many diet-related diseases like obesity and diabetes.”

Looking Beyond the Neighborhood Market 

De la Haye has worked with families across LA – from Lancaster to LA’s eastside – helping them with strategies to avoid unhealthy foods and adopt healthier eating habits. She said, “So I brought this real-world knowledge of the challenges Angelenos face in eating a healthy diet to our research project.” 

The team knew from their own experiences, and from the experiences of families they’ve worked with in healthy eating programs, that people don’t just eat in their home neighborhood. But they needed the data to prove this at the population scale. Horn said, “We thought that the lack of data showing all of the places where people actually go to eat and where they’re spending the most time might explain why we’re not seeing associations between the home neighborhood food environment and people’s diet and health outcomes.”

So they turned to smartphones for the data.

For most of us, our smartphone is always tracking our location, and we probably share that data with several apps. Location data companies aggregate this data – called “mobility data” – and sell it for advertising. But increasingly, it is being made available for research, such as by Spectus.ai through their Social Impact Program, through which the data for this study was obtained. 

Esteban Moro led the team at MIT that would help access and analyze this data. Moro, a Research Scientist at MIT Connection Science said, “Our group has a great deal of experience analyzing and using mobility data in problems like segregation, transportation, urban planning, and commercial activity. We are experts in analyzing large datasets of human behavior and transforming them into insightful tools for urban problems. So, our main role in this research was to provide and analyze population-wide mobility data about food consumption.” 

Bringing Together All the Data 

Using census block data for Los Angeles County to indicate home neighborhoods, and big mobility data to track daily trajectories, the researchers could see all of the proximity – the “exposures” – people would have to food outlets throughout their days. 

The team looked specifically at fast-food outlets because fast food is commonly consumed and strongly linked with disease risk. Using “point of interest” data they identified fast-food outlets within LA County. To bring in the health piece of the puzzle, they accessed survey data from the LA County Health Department. 

“The Los Angeles County Health Department does a health survey of the LA population every three years. We formed a collaboration with them, and they were able to share anonymized individual level data with us on socio-demographics, obesity rates, diabetes rates, and very importantly, fast-food intake frequency for a representative sample of the LA population,” said Horn. 

By analyzing the data, the researchers confirmed that your home neighborhood matters when it comes to your risk of diet-related disease, but so does your commute, the path you take to run your daily errands, how you get from point A to point B and all the way to point Z in your day, and what those points are. 

The Results? 

“We know there is a relationship between fast-food outlet visits and fast-food intake, as well as between fast-food intake and diet-related diseases, but wow, this data source does a really good job of capturing that!” said Horn. 

Moro elaborated, “The most surprising result is that mobility data works like a “honest signal,” i.e., visits to fast-food outlets were a better predictor of individuals’ obesity and diabetes than their self-reported fast-food intake, controlling for other known risks.”

De la Haye emphasized, “This work demonstrates that large-scale mobility data is in fact a valuable indicator of where and what people eat, and their risk for diet-related disease.” 

Why is this so significant?

De la Haye explained, “Measuring what people eat is really difficult. In fact, many large public health surveys and surveillance tools have stopped asking people about their food intake because the data is often unreliable (in part because people often forget the details of what they ate, and also because they don’t always want to tell researchers about their less healthy food choices). So, this gives us a new tool to track dietary patterns, like eating fast food, for large populations such as residents of cities, counties, or the entire country.” 

What’s Next? 

“What I’m excited about as a researcher,” said Horn, “is that this opens up mobility data for all kinds of investigations into the food environment. Things like: where are people getting food at different times of day? Who are these people? When are they most influenced by the options available (or unavailable) to them? We can really investigate this with big mobility data, because it allows us to look at eating behaviors in large and new dimensions: at scale across the population, across diverse population groups, diverse environmental surroundings, and over long periods of time.” 

De la Haye underscores the importance of this, “data on population dietary patterns is a powerful tool needed to make public health programs and policies, and ultimately reduce health risks from one of the leading causes of illness and death in the U.S.: unhealthy diets.” 

Would taxing sugar-sweetened beverages improve population health and save money? Is this the “nudging society” gone too far?

Taxing sugar-sweetened beverages in Germany would improve population health and save money

A tiered tax system that incentivizes companies to reduce sugar content has greatest impact

Researchers model the taxation of sugar-sweetened beverages with population health and overall healthcare costs in Germany. CREDIT Leiada Krozjhen, Unsplash (CC0, https://creativecommons.org/publicdomain/zero/1.0/deed.en)

In Germany, taxing sugar-sweetened beverages could prevent or postpone cases of type 2 diabetes, extend healthy lifespans and save up to €16.0 billion in societal costs over the next 20 years, according to a new study led by Karl Emmert-Fees of the Technical University of Munich, published November 21st in the open access journal PLOS Medicine.

The World Health Organization has recommended that governments worldwide lessen the social and economic burden of cardiometabolic disease by taxing sugar-sweetened beverages. These taxes either reduce consumption by increasing the price, such as the one peso per liter tax in Mexico, or incentivize companies to reformulate their drinks with a lower sugar content, such as the tiered tax structure in the United Kingdom. Germany has not yet implemented a tax on sugar-sweetened beverages, so researchers estimated the health and economic impacts of these two possible taxation scenarios.

Through modeling, the researchers predicted the effects of a 20% tax on sugar-sweetened beverages and a tiered tax similar to the one used in the United Kingdom. For each scenario, they estimated changes in sugar consumption, weight, associated medical and societal costs, and the risk of type 2 diabetes, heart disease and stroke, from 2023 to 2043.

The researchers discovered that during the next 20 years, a tax on sugar-sweetened beverages could reduce sugar intake in the German adult population on average by 1 gram per day, prevent or postpone more than 132,000 cases of type 2 diabetes and save €9.6 billion by encouraging consumers to change their behavior. A tiered structure, however, would reduce sugar consumption on average by 2.34 grams per day, prevent or postpone more than 244,000 cases of type 2 diabetes and save €16.0 billion by incentivizing companies to sell drinks with less sugar.

While both tax systems would help reduce the health burden and societal costs of cardiometabolic disease, the researchers conclude that a tiered tax would likely have the largest impact. The researchers conclude that taxing sugar-sweetened beverages would be a viable policy option for German decision makers that would improve the health of the German population.

Emmert-Fees adds, “Overall, we found that the taxation of sugar-sweetened beverages could have a substantial impact on population health in Germany. Particularly people who consume a lot of these beverages would benefit from the highest reduction in sugar intake.”

Research shows swapping out pulses for common proteins and grains improves our diet

Benefits of Swapping Grains for Pulses

Substituting ½ cup of pulses daily in place of one ounce of refined grains while keeping calories constant increases fibre, magnesium, copper, and potassium, a nutrient of concern, by more than 10% Coalition to Advance Pulses

  A recently published study[i] in Nutrients, an open-access peer-reviewed scientific journal, demonstrates that exchanging pulses for small amounts of typical protein sources and refined grains significantly improves the nutritional profile of the American diet.  This new research adds to the extensive established body of evidence showcasing the multiple benefits of including pulses in a healthy diet. 

Researchers modelled the nutritional impact of substituting servings of protein foods and/or refined grains with servings of pulses (e.g., dry peas, lentils, chickpeas, dry beans) while keeping calories consistent in the Healthy U.S.-Style Dietary Pattern identified in the 2020-2025 Dietary Guidelines for Americans.  Results showed an improved nutritional profile of the diet.  Specifically, the addition of about ¼ cup of pulses per day in place of one ounce per day of common protein foods increases fibre, a nutrient of concern, and decreases cholesterol, each by more than 10%.  Additionally, they found that substituting ½ cup of pulses daily instead of one ounce of refined grains while keeping calories constant increases fibre, magnesium, copper, and potassium, a nutrient of concern, by more than 10%. 

Our results suggest that encouraging increased pulse consumption may be an effective strategy for improving nutrient intake and achieving a healthier dietary pattern,” author Victor Fulgoni III, PhD, of Nutrition Impact, LLC.  “Pulses (dry peas, lentils, chickpeas, beans) are excellent sources of fibre, folate and potassium and good plant protein sources.”  The study was funded by the Coalition for the Advancement of Pulses.

The findings are consistent with the body of existing peer-reviewed studies that show the inclusion of pulses as part of a plant-forward dietary strategy imparts cardiovascular, metabolic, and gut protective effects; improves weight outcomes, and low-grade inflammation, and may play a role in immune-related disease risk management.[ii]  The American Heart Association and other public health organizations recommend adding more plant-based and less animal protein to reduce the risk of heart disease, high blood pressure and high cholesterol.[iii]

“This research underscores the fact that pulses are a nutritional powerhouse,” said Tim McGreevy, CEO, USA Dry Pea and Lentil Council and American Pulses Association.  “They are high in fiber, plant protein and several important macronutrients.  We know this and are working with our partners to increase awareness about the nutritional benefits of regular pulse consumption.”

Pulses are so nutritious that dietary guidelines globally include them in both the vegetable and/or protein food groups or as a separate food group all together. i, [iv],[v],[vi] The Dietary Guidelines for Americans 2020 – 2025 and the USDA’s Choose My Plate indicate that beans, peas, and lentils can be considered as part of the vegetable or protein groups.

Following a Mediterranean diet reduces the risk of cognitive decline in older people

Can Mediterranean diet help people with MS preserve thinking skills?
Can Mediterranean diet help people with MS preserve thinking skills?

According to a study published in the journal Molecular Nutrition and Food Research, old people who follow a Mediterranean diet are at a lower risk of cognitive decline. The study provides new evidence for a better understanding of the biological mechanisms related to the impact of the diet on cognitive health in the ageing population.

The study is led by Mireia Urpí-Sardá, adjunct lecturer and member of the Biomarkers and Nutritional & Food Metabolomics research group of the Faculty of Pharmacy and Food Sciences, the Institute for Nutrition and Food Safety (INSA-UB), the Food and Nutrition Torribera Campus of the University of Barcelona, and the CIBER on Frailty and Healthy Ageing (CIBERFES).

This European study, part of the Joint Programming Initiative “A Healthy Diet for a Healthy Life” (JPI HDHL) was carried out over twelve years and it involved 840 people over 65 years of age (65% of whom were women) in the Bourdeaux and Dijon regions of France.

Healthy diet and cognitive performance

According to Cristina Andrés-Lacueva, UB professor and head of the CIBERFES group, “within the framework of the study, a dietary metabolomic index has been designed —based on biomarkers obtained from the participants’ serum— on the food groups that form part of the Mediterranean diet. Once this index is known, its association with cognitive impairment is evaluated”.

in the study, baseline levels of saturated and unsaturated fatty acids, gut microbiota-derived polyphenol metabolites and other phytochemicals in serum that reflect individual bioavailability were chosen as biomarkers. Some of these indicators have not only been recognized as marks of exposure to the main food groups of the Mediterranean diet but have also been held responsible for the health benefits of the Mediterranean dietary pattern.

The metabolome or set of metabolites — related to food and derived from gut microbiota activity — was studied through a large-scale quantitative metabolomic analysis from the serum of the participants without dementia, from the beginning of the study. Cognitive impairment was assessed by five neuropsychological tests over twelve years.

As a result, the study reveals a protective association between the score of the Mediterranean diet based on serum biomarkers and cognitive decline in older people.

Biomarkers to study the benefits of the diet

According to Mercè Pallàs, professor at the UB Neurosciences Institute (UBneuro), “the use of dietary pattern indices based on food-intake biomarkers is a step forward towards the use of more accurate and objective dietary assessment methodologies that take into account important factors such as bioavailability”.

Expert Alba Tor-Roca, first author of the study and CIBERFES researcher at the UB, explains that “we found that adherence to Mediterranean diet assessed by a panel of dietary biomarkers is inversely associated with long-term cognitive decline in older people. These results support the use of these indicators in long-term follow-up assessments to observe the health benefits associated with the Mediterranean diet or other dietary patterns and therefore, guide personalized counselling at older ages”.