You may have recently been hearing about the health effects of ultra-processed foods. What foods fall into this category, exactly?
Ultra-processed foods are:
-Industrially produced
-Ready to eat
-Low in bioactive compounds like fiber, vitamins, minerals and phytochemicals
-High in salt, saturated fat, sugar, refined carbohydrates and food additives
Examples are frozen meals, soft drinks, hot dogs, fast food, packaged cookies, candies, cakes and chips.
The Study
The research literature consistently shows that exercise
is important to our health but is variety of exercise important? A study published
recently in the British Medical Journal attempted to find out.
Over 110,000 subjects from Harvard’s Nurses’ Health Study and Health Professional Follow-up Study had their exercise monitored and were followed for up to 34 years. An exercise variety score was created based on spending at least 20 minutes per week engaged in a wide variety of exercise.
The results were interesting:
-When comparing subjects with the highest exercise variety score to the lowest, there was a 19% lower risk of all-cause mortality.
-This benefit was independent of total physical activity. In other words, no matter how much total exercise you were getting, variety was associated with lower mortality.
doi:10.1136/bmjmed-2025-001513
Take Home Message
There appears to be a strong benefit to mixing up your exercise routine. Alternate different forms of cardio like walking or run-walking with gym equipment like elliptical trainers and Stair Masters. You can also build variety by trying different sports like tennis, ice skating, golf or skiing.
Why is this important? The researchers in this investigation believe that there are distinct physiological effects from different physical activities. These include a variety of ventilatory responses, muscles used and different nerve pathways utilized. Therefore, each type of exercise has its own unique health benefits, so the more variety, the better.
The Study
Proponents of low fat diets and proponents of low carb diets have been battling it out for decades. This study wanted to find out which was better for risk of heart disease. Over 200,000 participants in Harvard’s Health Professional Follow-up Study, Nurses’ Health Study and Nurses’ Health Study 2 had their diet measured repeatedly and were followed for up to 32 years for incidence of coronary heart disease.
A scoring system was created for a healthy version of each diet (lean proteins, plant oils and unrefined grains) as well as an unhealthy version (fattier animal-based proteins, saturated fats and refined grains).
The results showed that when healthy foods were chosen, risk for heart disease decreased and when unhealthy foods were chosen, risk went up. In other words, the amount of carb or fat didn’t really matter, just the quality of the food that was consumed. A low carb diet could be protective or risky, as could a low fat diet.
doi: 10.1016/j.jacc.2025.12.038
Take Home Message
Whatever diet you are following, focus on healthy carbs (fruits, vegetables, whole grains and legumes), healthy fats (olive oil, nuts, avocados) and healthy proteins (lean meats, seafood and lots of plant protein like beans and lentils).
This study shows that you really don’t need to get too caught up on the percentages of protein, fat and carbohydrate. Just make good choices.
Step counters have become a common feature of wearable technology and many of us are tracking how many steps we are taking each day. This begs the question of just how many steps do we really need to improve our health? A common answer is 10,000 steps, but there isn’t a whole lot of science behind this number.
The Study
This interesting investigation appeared in JAMA Internal Medicine several years ago. 17,708 subjects with a mean baseline age of 72 years from the Women’s Health Study wore accelerometers for a 4 year follow up (Reference 1). By the end of this time, 504 women had died.
The women were split into quartiles depending on the average number of steps taken per day. The results were a bit surprising:
The 1st quartile averaged 2,718 steps per day and was the reference group (the group the other quartiles were compared to).
The 2nd quartile averaged 4,363 steps per day and had a 46% lower risk of death from any cause when compared to the 1st quartile.
The 3rd quartile averaged 5,905 steps per day and had a 53% lower risk of death from any cause.
The 4th quartile averaged 8,442 steps per day and had a 66% lower risk of death from any cause.
There were a couple of other surprising findings:
-The mortality benefit leveled off at 7,500 steps. Doing more than this
did not really improve risk of dying from any cause.
-Step intensity wasn’t particularly important. The number of steps is all that really mattered. In other words, how fast you walked did not appreciably impact the reduction in risk of dying from any cause.
Conclusions And Recommendations
I think it is great when fitness and nutrition theories are put to the
test of a well-designed research study.
A few take home messages:
-If your goal is general health improvement and chronic disease risk reduction, don’t worry about hitting 10,000 steps per day, 7,500 will get the job done.
-Don’t worry about how fast you are walking. It does not seem to matter all that much.
-If your goal is weight loss, higher intensity and longer duration of cardio is likely more important.
-It is not all or nothing. Although the sweet spot for improved health was 7,500 steps, significant benefit was found in subjects walking just over 4,000 steps per day.
References
1) JAMA Intern Med. 2019;179(8):1105-1112
