Slowing down to eat less: towards simple strategies for obesity prevention

 

Research suggests that behavioral changes like chewing more and taking smaller bites can make a big difference in preventing overeating

Peer-Reviewed Publication

Obesity is linked to numerous health complications, including diabetes, cardiovascular disease, and fatty liver disease. In a world where obesity rates continue to climb, researchers are constantly seeking effective, accessible solutions to this global health crisis. Interestingly, over the past few decades, scientists have begun to focus not only on what we eat but also on how we eat it.

While much attention has indeed focused on dietary content and caloric intake, emerging research suggests that eating behaviors—including meal duration, chewing speed, and number of bites taken—may have a big impact on how much food we consume. Previous studies have indicated that people who eat more slowly tend to consume less food overall, but specific, evidence-based guidelines on how to effectively slow down eating have been lacking. This is particularly true for Japan, where eating habits differ from Western norms.

Against this backdrop, a research team led by Professor Katsumi Iizuka from the Department of Clinical Nutrition, Fujita Health University, Japan, conducted a study to identify factors that influence meal duration and eating behavior. Their paper, co-authored by Dr. Megumi Aoshima and Dr. Kanako Deguchi from Fujita Health University and published in Volume 17, Issue 6 of Nutrients journal on March 10, 2025, explores factors including sex differences, chewing patterns, and external rhythmic stimuli and their relationship to how we consume our meals. “While nutritional science is often concerned with food metabolism and absorption and dietary content, there’s limited evidence in Japan on dietary behavior that connects the two. This intrigued me to study eating behavior, which involves gender differences,” explains Iizuka.

The study involved 33 healthy participants aged 20 to 65 years who were asked to eat slices of pizza under different conditions. Researchers measured meal duration, number of chews, number of bites, and chewing tempo (the rate or speed of chewing), noting how these variables changed when participants were exposed to different metronome rhythms using headphones.

The results revealed significant differences between men and women in eating behaviors. Women typically took longer to eat, averaging 87 seconds compared to 63 seconds for men. They also chewed more (averages of 107 vs. 80) and took more bites (4.5 vs. 2.1). However, the actual chewing tempo was similar between both sexes.

When adjusted for sex differences, meal duration was positively associated with the number of chews and bites taken, but not with body mass index or average eating tempo. Perhaps most interestingly, when participants were exposed to a slow metronome rhythm of about 40 beats per minute, their meal duration increased significantly compared to eating without rhythmic stimulation.

The study suggests several straightforward strategies to extend meal duration: increasing the number of chews per bite, taking smaller bites (which naturally increases the total number of bites per meal), and potentially creating a slower eating environment through calming music or rhythmic cues. “These are easy, money-saving measures that can be started right away to help prevent obesity,” says Iizuka, highlighting the practical implications of the results.

These findings have particular relevance for nutritional guidance and obesity prevention programs. Rather than focusing solely on food content, interventions could incorporate guidance on eating behaviors and environmental factors that promote slower eating. “Incorporating the proposed eating behavior into school lunches and other programs can lead to the prevention of future diseases related to obesity,” Iizuka notes.

The researchers acknowledge that future studies should test these findings with a variety of foods beyond pizza to confirm their applicability in diverse eating scenarios. Nevertheless, this research provides valuable evidence-based strategies that could be incorporated into obesity prevention and treatment programs immediately, without significant cost or complexity.

Hopefully, these efforts will help spread actionable advice to both prevent and address obesity and minimize its impact on health down the line.

New mums advised to do two hours of moderate to vigorous exercise a week

 

Daily pelvic floor muscle training also strongly recommended. Following this new guideline is likely to result in large improvements in maternal and infant health and well-being, say experts

Peer-Reviewed Publication

BMJ Group

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New mums should be strongly encouraged to begin clocking up at least two hours of moderate to vigorous intensity physical activity such as brisk walking and muscle strengthening exercises each week in the first three months after birth, when physically able, to improve health and well-being, say experts in a new guideline published by the British Journal of Sports Medicine.

 

They also strongly recommend daily pelvic floor muscle training to reduce the risk of urinary incontinence, and taking steps to improve sleep quality and duration.

In the weeks and months following birth (postpartum period), risk of depression, weight retention, sleep disorders, diabetes, and cardiovascular disease increases, especially after pregnancy complications. But clear guidance on how to appropriately engage in postpartum physical activity is severely lacking.

To address this, a panel of expert researchers and clinicians set out to provide up to date, evidence-based guidance on physical activity, sedentary behaviour, and sleep throughout the first year after childbirth.

Their recommendations are based on in-depth analyses of evidence from 574 studies and are relevant to those who have recently given birth, irrespective of breastfeeding status, gender, cultural background, disability, or socio-economic status. 

After consulting with new mums, the panel selected 21 ‘critical’ and ‘important’ outcomes for analysis. These included injury, reduced breast milk quality or quantity, depression and anxiety, urinary incontinence, fear of movement, fatigue, and poor infant growth and development.

The quality and certainty of evidence for each outcome was evaluated using the GRADE system.

Based on this evidence, the panel strongly recommends that in the first 12 weeks after giving birth, new mums with no conditions or symptoms preventing them from being physically active should aim for a mix of aerobic and resistance activities (eg, brisk walking, cycling and muscle strengthening exercises) for at least 120 minutes each week, spread over four or more days of the week.

Those with underlying conditions or symptoms should seek medical advice before beginning or returning to moderate physical activity, they add. However, they stress that everyone who has recently given birth should be doing light daily activities such as gentle walking, to prevent the known harms of inactivity.

Other strong recommendations include daily pelvic floor muscle training to reduce the risk of urinary incontinence and rehabilitate pelvic floor muscles, and developing a healthy sleep routine (eg, avoiding screen time and maintaining a dark, quiet environment before bed) to support mental health.

New mums who follow this guideline, produced by the Canadian Society for Exercise Physiology, are likely to reap many health benefits, including reduced depression, urinary incontinence, and low back pain, and improvements in weight, cholesterol levels, and fatigue, with no increased risk of injury or adverse effects on breastmilk quality or quantity, they explain.

They acknowledge that meeting these recommendations may not always be possible, but say “even small steps towards achieving them will still promote physical and mental health benefits.”

And while future research will need to address gaps in the literature, they argue that these clinically meaningful benefits “strongly support incorporating consultation and guidance on movement behaviours into clinical practice for the postpartum period.”

Feedback also indicates that following these recommendations would be feasible, acceptable and equitable, and likely to incur minimal costs to individuals and health systems, while yielding significant healthcare savings.

 

Healthy eating in midlife linked to overall healthy aging

Key points:

• Maintaining a healthy diet rich in plant-based foods, with low to moderate intake of healthy animal-based foods and lower intake of ultra-processed foods, was linked to a higher likelihood of healthy aging—defined as reaching age 70 free of major chronic diseases, with cognitive, physical, and mental health maintained—according to a 30-year study of food habits among more than 105,000 middle-aged adults.
• All the eight dietary patterns studied were associated with healthy aging, suggesting that there is no one-size-fits-all healthy diet. 
• The study is among the first to examine dietary patterns in relation to overall healthy aging, rather than in relation to specific diseases or mortality.

Boston, MA—Maintaining a healthy diet rich in plant-based foods, with low to moderate intake of healthy animal-based foods and lower intake of ultra-processed foods, was linked to a higher likelihood of healthy aging—defined as reaching age 70 free of major chronic diseases and with cognitive, physical, and mental health maintained, according to a new study by researchers at Harvard T.H. Chan School of Public Health, University of Copenhagen, and University of Montreal. The study is among the first to examine multiple dietary patterns in midlife in relation to overall healthy aging.

“Studies have previously investigated dietary patterns in the context of specific diseases or how long people live. Ours takes a multifaceted view, asking, how does diet impact people’s ability to live independently and enjoy a good quality of life as they age?” said co-corresponding author Frank Hu, Fredrick J. Stare Professor of Nutrition and Epidemiology and chair of the Department of Nutrition at Harvard Chan School.

The study will be published March 24 in Nature Medicine.

The researchers used data from the Nurses’ Health Study and the Health Professionals Follow-Up Study to examine the midlife diets and eventual health outcomes of more than 105,000 women and men ages 39-69 over the course of 30 years. Participants regularly completed dietary questionnaires, which the researchers scored on how well participants adhered to eight healthy dietary patterns: the Alternative Healthy Eating Index (AHEI), the Alternative Mediterranean Index (aMED), the Dietary Approaches to Stop Hypertension (DASH), the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND), the healthful plant-based diet (hPDI), the Planetary Health Diet Index (PHDI), the empirically inflammatory dietary pattern (EDIP), and the empirical dietary index for hyperinsulinemia (EDIH). Each of these diets emphasizes high intake of fruits, vegetables, whole grains, unsaturated fats, nuts, and legumes, and some also include low to moderate intake of healthy animal-based foods such as fish and certain dairy products. The researchers also assessed participants’ intake of ultra-processed foods, which are industrially manufactured, often containing artificial ingredients, added sugars, sodium, and unhealthy fats.

The study found that 9,771 participants—9.3% of the study population—aged healthfully. Adhering to any one of the healthy dietary patterns was linked to overall healthy aging and its individual domains, including cognitive, physical, and mental health.

The leading healthy diet was the AHEI, which was developed to prevent chronic diseases. Participants in the highest quintile of the AHEI score had an 86% greater likelihood of healthy aging at 70 years and a 2.2-fold higher likelihood of healthy aging at 75 years compared to those in the lowest quintile of the AHEI score. The AHEI diet reflects a diet rich in fruits, vegetables, whole grains, nuts, legumes, and healthy fats and low in red and processed meats, sugar-sweetened beverages, sodium, and refined grains. Another leading diet for healthy aging was the PHDI, which considers both human and environmental health by emphasizing plant-based foods and minimizing animal-based foods. 

Higher intake of ultra-processed foods, especially processed meat and sugary and diet beverages, was associated with lower chances of healthy aging. 

“Since staying active and independent is a priority for both individuals and public health, research on healthy aging is essential,” said co-corresponding author Marta Guasch-Ferré, associate professor in the Department of Public Health at the University of Copenhagen and adjunct associate professor of nutrition at Harvard Chan School. “Our findings suggest that dietary patterns rich in plant-based foods, with moderate inclusion of healthy animal-based foods, may promote overall healthy aging and help shape future dietary guidelines.”

“Our findings also show that there is no one-size-fits-all diet. Healthy diets can be adapted to fit individual needs and preferences,” added lead author Anne-Julie Tessier, assistant professor in the Department of Nutrition at the University of Montreal, researcher at the Montreal Heart Institute, and visiting scientist at Harvard Chan School.

The study had some limitations, notably that the study population was composed exclusively of health professionals. The researchers noted that replicating the study among populations with diverse socioeconomic statuses and ancestries would offer further insights into the findings’ generalizability.

Eating chili during pregnancy help lower the risk of gestational diabetes

 As lean sources of protein, complex carbohydrates and fiber, beans are known worldwide as providing lots of nutritional power at a very affordable price. Now, a University at Buffalo study suggests that when consumed in chili during pregnancy, beans may help lower one’s risk for gestational diabetes.

The study was published on March 14 in the journal Nutrients.

While the UB researchers caution that the study was relatively small and needs to be replicated in a larger cohort, they note that the findings are important given the steady increase in gestational diabetes. Recent national data from the Centers for Disease Control and Prevention shows that the prevalence of gestational diabetes in the U.S. increased from 6% in 2016 to 8.3% in 2021.

Gestational diabetes is diabetes that is initially diagnosed during pregnancy; if untreated, it can adversely affect the health of both mother and baby. While it often goes away after pregnancy, it can put the mother at higher risk for developing Type 2 diabetes later in life. Risk factors include pre-pregnancy obesity, excessive weight gain during pregnancy, advanced maternal age, unhealthy diet, insufficient physical activity, and COVID-19.

Beans can improve glycemic control

Because of their excellent nutritional profile, beans and their possible health benefits during pregnancy were of interest to the UB researchers. Previous studies have shown that diets high in beans and other legumes can lead to healthier levels of blood sugars and significantly lower the risk of developing Type 2 diabetes, possibly because of their high fiber content and other beneficial components. However, few studies have focused on how they might affect gestational diabetes, especially in individuals eating a typical American diet.

“Our research aimed to study the roles of bean consumption in gestational diabetes, including chili, dried beans and bean soup,” says Xiaozhong Wen, MD, PhD, first author and associate professor of pediatrics in the Division of Behavioral Medicine in the Jacobs School of Medicine and Biomedical Sciences at UB. “Interestingly, only chili consumption was statistically significantly associated with the risk of gestational diabetes.”

The researchers found that pregnant women who ate chili once per month had a 3.5% risk of developing gestational diabetes, compared to 7.4% for expectant mothers who never ate chili.

Capsaicin and phenolic compounds

The reasons why only chili was found to be associated with a low risk of gestational diabetes are not yet understood. However, the researchers note that some of the components that may be specific to chili, such as capsaicin, an extract of chili powder, and phenolic compounds in beans, especially the dark beans typically used in chili, have been linked to improved blood sugars.

“Both human and animal studies have shown that capsaicin and phenolic compounds have some potential benefits of improving glycemic control through slowing glucose absorption and increasing insulin secretion and/or insulin sensitivity,” says Wen.

The study included 1,397 pregnant women and was based on a secondary data analysis within a U.S. national cohort study named Infant Feeding Practices Study II, which was conducted by the Food and Drug Administration in collaboration with the CDC. It enrolled mothers in late pregnancy and followed them and their infants up to 12 months postpartum.

Wen says the research findings need to be replicated in larger cohorts with more diverse populations, detailed measures of bean consumption and dietary intake information collected more frequently and a randomized controlled design.

He adds that given the non-causal nature of observational research, recall bias and selection bias, the findings should be interpreted cautiously.

So should pregnant individuals, especially those who might be at risk of developing gestational diabetes, consider adding chili into their diets?

“Moderate chili consumption may be incorporated into a balanced diet approach to addressing gestational diabetes, along with other clinical recommendations, such as early screening, diagnosis, exercise and medications as needed,” says Wen.

Cholesterol-elevating substances in coffee from machines at work

 

Peer-Reviewed Publication

Uppsala University

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image: 

David Iggman, docent and researcher at the Department of Public Health and Caring Sciences, Uppsala University

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Credit: Region Dalarna

The coffee from most of the coffee machines in workplaces contains relatively high levels of cholesterol-elevating substances. There is a big difference in comparison to coffee made in regular paper filter coffee makers, which filter out most of these substances.

This has been shown in a new study led from Uppsala University, and conducted in collaboration with Chalmers University of Technology. The study is published in the journal Nutrition, Metabolism & Cardiovascular Diseases. 

“Considering how much coffee is consumed in Swedish workplaces, we wanted to get a picture of the content of cholesterol-elevating substances in coffee from these types of machines. We studied fourteen coffee machines and could see that the levels of these substances are much higher in coffee from these machines than from regular drip-filter coffee makers. From this we infer that the filtering process is crucial for the presence of these cholesterol-elevating substances in coffee. Obviously, not all coffee machines manage to filter them out. But the problem varies between different types of coffee machines, and the concentrations also showed large variations over time,” says David Iggman, researcher at Uppsala University, who led the study.

The fact that boiled coffee in a pot contains high levels of the worst of the cholesterol-elevating substances, the diterpenes cafestol and kahweol, is already known. It’s even mentioned in the latest Nordic nutritional recommendations, where the advice is to reduce or refrain from drinking boiled coffee. However, a regular drip-filter coffee maker, which uses a paper filter, manages to almost completely filter out these cholesterol-elevating substances. 

How well conventional coffee machines, which are found in public environments such as workplaces, filter out these substances had not been investigated up until now. In the study, the researchers studied fourteen coffee machines in break rooms at different workplaces. The coffee used was five regular brands of ground coffee. They took samples from the coffee made by the machines on a number of separate occasions and analysed the contents. There was a big difference between the machines in terms of the levels of cafestol and kahweol in the coffee they made, but the levels could also differ at different times. 

The most common type of coffee machine, in the study called a brewing machine, is the one that produced coffee with the highest concentrations of diterpenes. In comparative analyses, the researchers  investigated peculator coffee, espresso, French press coffee, boiled coffee, and boiled coffee poured through a fabric filter. The boiled coffee contained the highest levels of diterpenes per cup. Some espresso samples also contained high levels, but there was great variation.

“Most of the coffee samples contained levels that could feasibly affect the levels of LDL cholesterol of people who drank the coffee, as well as their future risk of cardiovascular disease. For people who drink a lot of coffee every day, it’s clear that drip-filter coffee, or other well-filtered coffee, is preferable. To determine the precise effects on LDL cholesterol levels, we would need to conduct a controlled study of subjects who would drink the coffee,” says David Iggman.

 

Facts in brief
Two samples were taken from each machine every two to three weeks. The coffee varieties included medium roast and dark roast of five common brands of ground coffee. Most of the machines use ground coffee. One or two grind the beans in the machine, but the researchers don’t think that would have any effect on the levels of diterpenes. We tested 14 machines, including 11 brewing machines and 3 liquid-model machines (lower levels, mixed from a coffee concentrate). For comparison, the same analysis was carried out with some other coffee-making methods such as percolator, French press, boiled coffee, and boiled coffee poured through a fabric filter. In addition, four espresso samples were collected in Gothenburg. All the coffee samples were analysed at Chalmers University of Technology. The samples were collected by medical student Erik Orrje during spring 2024.

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Journal

Nutrition Metabolism and Cardiovascular Diseases

DOI

10.1016/j.numecd.2025.103933 

Why are night owls at greater risk of depression?

 Mindfulness, total sleep quality, and alcohol consumption may help explain why people who stay up late have a greater risk of depression, according to a new study publishing March 19, 2025, in the open-access journal PLOS One by Simon Evans of University of Surrey, UK, and colleagues.

Previous research has shown that night owls who stay up late, called “evening chronotypes,” have more depression symptoms than people who are early risers, or “morning chronotypes.” In the new study, Evans and colleagues collected data from 546 university students using an online questionnaire. The data included self-reported information on the students’ sleep patterns, mindfulness, rumination tendencies, alcohol use, and depression and anxiety levels.

The study confirmed that people with an evening chronotype were at a notably higher risk for depression and that the association could be explained by differences in mindfulness, sleep quality, and alcohol consumption. On average, evening chronotypes had poorer sleep quality, higher alcohol consumption, and acted with less mindfulness than morning chronotypes.

The study was limited in its ability to prove cause-and-effect because of its cross-sectional design which relied on data at only one time point. In addition, the findings may not apply to age groups outside of the university students included in the study.

With those caveats in mind, the authors conclude that interventions aimed at mindfulness, sleep and alcohol use might have the potential to reduce depression risk, amongst young adults in particular.

The authors add: “With many young adults’ experiencing poor mental health, these study findings are particularly important—many young adults tend to stay up late and the results point to how interventions could be implemented to reduce their risk of depression.”

 The freely available article in PLOS One: https://plos.io/3DtXmiM

People with obesity, diabetes and heart disease—could live longer with a healthy plant-based diet

 People with cardiometabolic disorders—such as obesity, diabetes and heart disease—could increase their chances of living longer by adopting a healthy plant-based diet, according to a study being presented at the American College of Cardiology’s Annual Scientific Session (ACC.25).

While previous studies have assessed the benefits of plant-based diets in a general population, this new study is the first to focus on their benefits in people with cardiometabolic disorders, which are rising in prevalence worldwide and bring an increased risk of premature death.

“Among populations with cardiometabolic disorders, higher adherence to a healthful plant-based diet was significantly associated with a lower risk of total, cardiovascular and cancer mortality,” said Zhangling Chen, MD, PhD, of the Department of Cardiovascular Medicine at the Second Xiangya Hospital of Central South University in Changsha, China, and the study’s lead author. “More intake of healthy plant-based foods, less intake of unhealthy plant-based foods and less intake of animal-based foods are all important.”

Cardiometabolic disorders stem from a variety of genetic, environmental and lifestyle factors and affect the health of the cardiovascular system and how the body processes food. While some medications can help manage these disorders, diet and other lifestyle factors are key in preventing the progression to serious forms of heart disease and cancer that are associated with cardiometabolic disorders.

Researchers analyzed data from nearly 78,000 people with cardiometabolic disorders who participated in large prospective studies in the United Kingdom, United States and China. The pooled datasets included 55,000 adults from the U.K. Biobank (UKB) between 2006-2022, 18,000 U.S. adults from the National Health and Nutrition Examination Study (NHANES) between 1999-2018 and almost 4,500 Chinese adults from the Chinese Longitudinal Healthy Longevity Study (CLHLS) between 2006-2018.

Based on their responses to 24-hour dietary recall interviews or dietary questionnaires at baseline, researchers assigned each participant a score on two indexes. People who reported a diet high in healthy plant-based foods such as vegetables, fruits, whole grains, legumes, tea and coffee scored higher on the healthful plant-based diet index, while those who reported a diet higher in refined grains, potatoes, sugar-sweetened beverages and animal-based foods scored higher on the unhealthful.

Overall, closer adherence to a healthful plant-based diet was associated with a 17% to 24% lower risk of death from any cause, cardiovascular disease or cancer, while closer adherence to an unhealthful plant-based diet brought a 28% to 36% increased risk of death from any cause, cardiovascular disease or cancer.

For the analysis, researchers adjusted for confounding factors such as demographics, dietary and lifestyle factors. Results were consistent across subgroups by age, race, sex, smoking, alcohol intake, body mass index and physical activity. They were also consistent in people with different types of cardiometabolic disorders and in people from the U.K., U.S. and Chinese cohorts when these groups were analyzed separately, even though the U.K. and U.S. groups were significantly younger, with an average age of 57 years and 59 years, respectively, compared with the Chinese group, which had an average age of 84 years.

In a separate study that only used NHANES data and did not focus on people with cardiometabolic disorders, the same research group found that a greater adherence to a healthy beverage pattern was associated with a lower risk of premature death. They defined a healthy beverage pattern as one high in tea, coffee and low-fat milk and low in alcohol, whole-fat milk, fruit juice and sugar-sweetened and artificially sweetened beverages.

“These findings may help individuals with cardiometabolic disorders make heathier lifestyle choices,” Chen said. “It is important to identify and develop cost-effective strategies to promote health among individuals with cardiometabolic disorders.”

For both studies, the researchers said that dietary data were self-reported by study participants at baseline and not assessed again, so the studies were not able to reflect any dietary changes participants may have made. They added that some potentially confounding factors were difficult to eliminate and suggested that additional prospective studies in diverse global populations would help to strengthen the evidence and confirm the importance of healthy food and beverage consumption patterns in broader populations.