Alexandra Ross, PhD, MHS  

High sodium intake is associated with hypertension, heart disease, and strokes, making it a public health concern across the globe. However, reducing sodium consumption can be challenging due to the high levels present in packaged foods. Recognizing this public health concern, South Africa tackled this issue head-on by passing sodium reduction regulations—and the United States has proposed their own targets on a voluntary basis. So, what can we learn from South Africa’s approach?

The South African National Health and Nutrition Examination Survey previously reported that approximately one-third of adults over the age of 15 experience hypertension. To address this issue, South Africa introduced mandatory sodium reduction targets in 2013, requiring food manufacturers to progressively lower sodium levels in key processed food categories, such as processed meats, soup powders, breads, condiments, and ready to eat savory snacks.  Colleagues found changes have been associated with reductions in blood pressure measurements.
 
To evaluate the effects of these regulations, in a brief study with my South African colleagues, we analyzed sodium intake changes in a low-income township. We compared sodium levels in foods reported in 24-hour dietary recalls before and after the regulations took effect, using updated food composition tables.
 
We found that sodium levels across multiple food groups were lower due to changes at the manufacturing level (reformulation), especially in salami meats, soup from powder mixes, nuts and seeds, and breakfast cereals. Additionally, mean sodium intake declined, with the most pronounced reductions being among high consumers (those exceeding World Health Organization’s 2000 mg/day recommendation).
 
Our study showed that reformulation of products alone can reduce sodium intake in popular foods people already consume. In reality, healthy dietary changes are even more significant when combined with education and policy awareness. Public discussions around sodium reduction can help shape consumer choices, reinforcing the idea that healthier options were available and beneficial. This highlights the importance of pairing regulatory efforts with public health campaigns to support lasting behavior change.
 
Lessons for the United States
As the FDA considers sodium reduction targets, South Africa’s experience demonstrates that regulatory interventions can successfully decrease sodium consumption. Given the challenges of individual behavior change in dietary habits, reformulation of processed foods offers a pragmatic approach to improving population health without requiring significant effort from consumers. However, complementary public health strategies are essential for maximizing the impact, such as:

• Develop public education campaigns to increase awareness of sodium’s health risks and promote acceptance of lower-sodium foods. For example, bread is not considered a high sodium food but is the largest contributor of added sodium in the diet among South Africans. Understanding the food categories where most sodium consumption comes from can guide behaviors and education.
• Consider cultural acceptability of the reduced targets. South Africa had higher thresholds for specific foods, like salt-and-vinegar crisps – a favorite among South Africans – to improve public acceptance. All other crisp flavors were subject to the lower sodium regulations. 
• Create clear front-of-package labeling to facilitate informed consumer choices. South Africa is implementing a multi-level packaging system to help keep consumers informed about the foods they are purchasing.
• Provide industry incentives and regulation enforcements to ensure consistent and widespread compliance. South Africa’s target reductions have been considered successful due to its mandatory implementation.
• Implement policies for restaurants to encourage sodium reduction beyond packaged foods. A concern is that consumers might compensate for lower sodium levels in processed foods by adding table salt or consuming more restaurant-prepared meals.

 
Conclusion
South Africa’s experience underscores that sodium reduction policies can lower dietary sodium intake and reduce chronic disease risk. However, these efforts must be supported by consumer education, enforcement, transparent labeling, and equitable food access initiatives. By learning from South Africa’s successes and challenges, the U.S. can adopt a powerful, nationwide sodium reduction strategy to improve public health outcomes – and guilt-free snacking!

Author
​Alexandra Ross is interested in policy-level interventions to improve food accessibility, particularly as it relates to food pricing and nutrition assistance programs. Her goal is to do research that will develop and evaluate programmatic strategies to improve the availability, financial accessibility, and desirability of foods to improve diet quality and subsequent chronic disease risk. Her previous work focuses on changes in the retail food environment, emphasizing food pricing, nutrient regulations, and international policy evaluations in the United States and South Africa. Dr. Ross earned her PhD in Nutrition Epidemiology from the University of North Carolina Gillings School of Global Public Health and an MHS in Social Factors in Health from the Johns Hopkins Bloomberg School of Public Health.

Soren Harnois-Leblanc, PhD

​Staying active and limiting sedentary time may require a bit more encouragement over these cold winter months. Here is one incentive: did you know that you can optimize your health by considering all movement behaviors and their influence on each other over a 24-hour period?

​The Physical Activity Guidelines for Americans, 2nd edition, provide age group- and condition-specific (such as pregnancy) guidelines for physical activity. For example, children and adolescents should get at least 60 minutes of moderate-to-vigorous physical activity daily, and for adults, it should be at least 150 minutes (or 2.5 hours) weekly. Brisk walking, shoveling, running, and taking an aerobics class are moderate-to-vigorous intensity activities. All age groups should also strive to include bone-strengthening physical activity at least three days a week. The Canadian 24-hour movement guidelines follow similar targets, but emphasize the importance of balancing physical activity with sedentary behaviors and sleep over a 24-hour period, as all three factors are interconnected.
 
That means we should look at our movement behaviors over a 24-hour period. Every little movement counts, such as taking the stairs, walking to work or during lunchtime, or even getting up from your chair at work to go get water or ask a question to a colleague throughout the day. So it may be that on a given day, you did not do your planned workout/preferred activity of the moment, but with the several non-structured activities, it accumulates to the daily 30 minutes that is minimally required by the guidelines, five days a week.
 
What else is different with the 24-hour movement concept? It highlights that the time we allocate to one behavior will affect the other behaviors. This is where it becomes even more motivating because you get a two-for-one benefit by making small changes. For example, by choosing to go on a walk after dinner with your significant other, you probably cut down 20 minutes of social media scrolling on the couch. Or by leaving your phone outside of the bedroom, you reduce screen time by allocating this time towards sleep.
 
Overall, by considering the integration of all three behaviors throughout the day, we realize that taking little actions can have huge benefits. One study in youth showed that even small increments in physical activity, by as little as 10 minutes a day, can improve insulin sensitivity and reduce insulin secretory requirements, potentially preventing prediabetes and type 2 diabetes. The study findings also suggest similar benefits by cutting down screen time by one hour a day. In another study in youth that considered all movement behaviors over 24 hours using compositional data analysis, vigorous physical activity relative to other behaviors was linked to lower waist circumference and higher HDL-cholesterol levels, therefore, in favor of better metabolic health. Lastly, a systematic review and meta-analysis found that adults who interrupted prolonged sitting periods with physical activity showed, on average, a lower rise in glycemia and lower insulin response following meals. Thus, regularly cutting work in a seated position with breaks (i.e., getting a cup of tea in the kitchen, doing some standing stretches), could protect against type 2 diabetes development.
 
Overall, until the nice weather returns, it can be helpful to remember that for your metabolic health, every little bit of physical activity counts – both structured and unstructured. It may be easier to stay active this time of year if you enjoy winter activities, and if not, just remember that small adjustments aimed at increasing physical activity and sleep are also beneficial.
 

Author
​Soren is a postdoctoral fellow in the Division of Chronic Disease Research Across the Lifecourse (CoRAL) in the Department of Population Medicine at Harvard Medical School and Harvard Pilgrim Health Care Institute. Her work supported by the Pyle award and the American Diabetes Association fellowship aims to better characterize the role of diet on diabetes risk markers from early childhood to late adolescence in Project Viva pre-birth cohort using causal inference methods. She additionally investigates how the associations between diet and diabetes risk markers differ based on the children’s sex assigned at birth and genetic predisposition to diabetes. More broadly, her research focuses on the prevention of obesity, type 2 diabetes and cardiovascular disease over the first decades of life. 
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​Imagine you’re navigating the bustling aisles of supermarkets after a tiring day of work, and your attention is quickly drawn by all convenience, ready-to-eat options prepared on site. These prepared foods don’t require any extensive cooking, a perfect match for your busy life. In the US, prepared foods in supermarkets are in high demand over the past decades because of their convenience. However, this convenience comes at a cost of low nutritional quality and raises public health concerns. Petimar et al. led a study published in 2023 that revealed the high calories and low nutrient density reality behind supermarket prepared foods. 

This study found a substantial growth in prepared foods in supermarkets over time (2015-2019) by investigating two supermarket chains in the US ~1200 stores. Both the percentage of prepared foods in overall food products and, the variety of prepared foods increased over time, doubling in 2019 (6.4%, 4113 items) compared to 2015 (3.1%, 1930 items).

Calories and other nutrients of concerns—sugar, saturated fat, and sodium—from prepared foods showed a slow, increasing trend when diving into both purchasing information at transaction level and nutrition information. However, the percentage of total nutrients purchased from prepared foods was stable over time, which may suggest consumers increased overall foods purchased.

Additionally, most of the prepared foods were high in calories, sugar, saturated fat and sodium. When looking at the variety of prepared foods, over 90% of prepared bakery and deli items, and 61% of prepared entrees had high calories or were high in at least 1 of the nutrients of concern. Prepared foods also showed similar nutritional profiles when compared with supermarket packaged foods and with restaurant foods.

These findings illustrate that prepared foods might be convenient for consumers to grab and go, but they showed very similar concerning nutritional profiles—high in calories, sugar, saturated fat, and sodium—as supermarket packaged foods and restaurant foods. The similar nutritional profiles between prepared foods and packaged foods might contradict consumers’ common sense as prepared on site could be healthier. A previous study found consumers may pay more attention to the packaged foods’ labels and  consider the nutritional content before purchasing. Policy and behavior interventions should be developed to better inform consumers about the nutrition values in prepared foods which could lead to healthier food choices when shopping at supermarkets.
 

Author 
Yutong Zhang is a Research Analyst at the Harvard Pilgrim Health Care Institute within the Division of Chronic Diseases Across the Lifecourse (CoRAL). She has a broad interest in nutrition epidemiology and food labeling policy. She holds a master's degree in Nutrition Intervention, Communication, and Behavior Change from Tufts University. Before joining CoRAL, she worked as a research assistant at Tufts Friedmann School of Nutrition Science and Policy focusing on nutritional data management and foodborne outbreak analysis. In her spare time, she enjoys traveling, hiking, and taking care of plants.

​Families with school aged children are probably familiar with the hecticness that accompanies a morning before school: waking up early, getting the kids showered and dressed, zipping up book reports and last night’s homework into backpacks, and squeezing in 10 minutes for breakfast before racing out the door to catch the bus. Thankfully, preparing breakfast and lunch are two tasks that parents no longer have to worry about each morning. With universal school meals, every child who wants or needs a school lunch or breakfast can receive those meals at no cost to their family. 

​In August 2023, Governor Healy and the Massachusetts Legislature made a monumental decision to make School Meals for All in Massachusetts permanent. Massachusetts is the 8th state to implement universal school meals, joining California, Colorado, Maine, Michigan, Minnesota, New Mexico, and Vermont. Additionally, 28 other states are currently working to expand free school meal legislation in the near future. This program covers the cost of one lunch and breakfast, including fruit, vegetables, and whole grains, as per the National School Lunch and Breakfast Programs.

During the pandemic, food insecurity reached the highest level in decades, amplifying the need for stable sources of nutritious meals for children. In October 2020, the Harvard T.H. Chan School of Public Health reported that every day, 14 million children were going hungry, and the percentage of U.S. households with children experiencing food insecurity doubled. But even with the pandemic behind us, the number of children living in food insecure households has not changed. In a report released by the U.S. Department of Agriculture in September 2024, it was reported that 13.5% of households in the U.S. were food insecure at least some time during 2023, including 14 million children – an increase of 1 million children from 2022.

States like Massachusetts are recognizing the protection that universal school meals can provide from the harmful and potentially long-lasting consequences of poor nutrition and unstable food sources. Studies show that children facing food insecurity have difficulty concentrating, decreased academic performance, increased behavioral issues, and increased illness. Additionally, food insecurity in children is associated with obesity, poor social functioning, and increased mental health issues.

In the 2022-2023 school year—the first year of state-funded universal school meals in Massachusetts—the state served 12.2 million more lunches than in the 2018-2019 school year. Additionally, 61,500 more students were served lunch at school every day. Research shows that participation in school meals improves academic achievement, attendance, and school behavior. Participation in school meals also provides nutritional and health benefits for children such as increased consumption of fruits, vegetables, and milk, and even reduced visits to the school nurse.
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When students participate in their school’s meal program, everyone benefits. Parents save time and money from having to prepare meals for their kids, schools receive additional revenue from the state to invest in their meal programs, and students can enjoy healthy and nutritious meals together while breaking down the stigma of participating in reduced meal programs. 

​Watching this past summer’s Olympics, one of my favorite breakout stars was Team USA Rugby player Ilona Maher. Maher has gained attention for promoting body positivity for young girls; she often talks about how her Body Mass Index (BMI) has always qualified her as overweight. While she was insecure about her larger size as a child, she now emphasizes her size allowed her to have the strength and athleticism to become a champion rugby player. As a mom with two young kids, Maher’s comments about BMI and childhood body image made me think about how frequently I see BMI numbers for my kids and how little I understand about what they mean, which led me to explore the topic.  

For each of my children’s After Visit Summaries (AVS) following pediatric visits, BMI is listed at the top. For children, BMIs are given a percentile and it is this that is used to categorize a child’s weight. The Center for Disease control provides the following definitions:

•  Underweight: less than 5th percentile
•  Healthy Weight: 5th to less than 85th percentile
•  Overweight: 85th to less than 95th percentile
•  Obese: 95th percentile or greater
•  Severe Obesity: 120% of the 95th percentile or greater 

While pediatricians have reported BMI for my children starting from birth, the American Academy of Pediatrics states that there are no accepted definitions for underweight, overweight, or obesity for children under two years of age. It is at age two that universal BMI screening is recommended for annual physicals.

Both physicians and parents can agree that a focus on childhood obesity prevention is important, both to mitigate possible health consequences facing children and to decrease the likelihood of obesity in adulthood. In fact, numerous studies have shown that children with obesity are more likely to also have obesity as adults. Early weight management in kids seems crucial; for example, a 2018 study found that a critical window for rapid weight gain is between the ages of two and six.

If early weight management is important, how do we monitor it? There are criticisms that BMI does not measure body fat or distribution and does not identify the factors leading to obesity in a patient. To address this, the American Medical Association issued a new policy in 2023 urging physicians to use other measurements, including visceral fat, body adiposity, waist circumference, and genetic/metabolic factors, as these measurements better predict obesity. Lending support to these recommendations, a study published in 2024 found that using waist circumference-to-height ratio is a more accurate predictor of fat mass in children compared to BMI.

Other studies suggest that physical activity levels, not BMI, have a greater impact on mortality. One metanalysis found that cardiorespiratory fitness predicted mortality risk better than BMI, with “fit” individuals categorized as overweight/obese having similar mortality risks to “fit” individuals with normal weights. In addition, “unfit” individuals had twice the mortality risk of “fit” individuals, regardless of BMI.

​However, despite growing debate regarding its use, BMI is still the CDC’s recommended obesity screening metric for children. Given this, when it comes to that ever-present BMI number, my takeaway is that it I shouldn’t fixate on it or let my children. It is just one piece of information to help understand the full health picture. As we saw this past summer, Olympic athletes come in many shapes and sizes, which highlights the significance of encouraging kids to discover the forms of physical activity that best suit their interests and abilities.