Healthy Food & Healthy Living by Dr. Ayala

Walking the streets, not just on Halloween

One of the pleasures of Halloween is that on and around this day kids are out and about, walking from home to home, trick-or-treating. They fill the streets.

Other days of the year, not so much.

Childhood obesity tripled in the last few decades, and if we were playing the blame game the obesogenic environment would be my target.

An obesogenic environment is one that makes it easy to take in lots of calories and spend fewer of them.

Its components include a setting with lots of high calorie tempting food around, mass media that promotes that food, and role models such as parents, friends or influencers engaging in eating habits that lead to weight gain.

But on top of the high-calorie food excesses, obesogenic environments support sedentary lifestyle and make it the default.

Kids are affected by their families, friends, home environment and their virtual – online – reality.

But they’re also a reflection of the place they live in.

Does a walkable neighborhood make you thin?

People in Manhattan and Paris are thinner than average. Does walking have anything to do with it? 

Neighborhood design can affect the way people behave, and when it comes to kids’ time outdoors, the ability to walk, bike and play outside may predict how often this actually happens.

What’s a walkable neighborhood? It’s pedestrian friendly – with safe sidewalks, well-connected streets, fewer busy intersections, and tree-shaded lanes. A walkable neighborhood has destinations to walk to: friends’ homes, parks, shops, schools, jobs, transit stops. A walkable neighborhood has safe streets to stroll.

Walkable neighborhoods have many benefits: They are happier, better for the environment (your feet don’t emit), help build a community, and they’re also healthier.

Unfortunately, many new suburbs were built as a subdivisions, around a cul-de-sac, with streets that empty into a busy road that’s hard to cross, and not within walking distance to schools, shopping or entertainment.

Does that affect the lives of suburban kids? Several studies show a correlation between neighborhood walkability and physical activity, obesity, as well as the incidence of type 2 diabetes.

But here’s the thing: People who enjoy walking and who are health conscious may chose to live in a walkable neighborhood – where you live isn’t random. Several studies which use sophisticated matching techniques find that the residential selection bias is modest, though, and when correcting for it, the link between walk-friendly neighborhoods and weight status still stands.

A new meta-analysis in Obesity Reviews examines how streets’ characteristics affect physical activity in kids, and to do so the researchers collected and analyzed all 47 relevant studies on the topic. The analysis found that living in streets that connect to other many other streets and create a network – as opposed to subdivisions and cul-de-sacs that empty into a major artery – is associated with kids engaging in more physical activity.

Walk safe

Our food environment has changed, but so have our neighborhoods. Too many neighborhoods aren’t walkable, and walking them isn’t always safe.

And here’s another disturbing statistic: While driving a car in the US is becoming safer and safer, year after year, walking is becoming less so. Pedestrian deaths rose by 50 percent in the last decade – in 2018 pedestrian deaths rose again by 3.4 percent, cyclist fatalities by 6.3 percent, continuing this alarming trend.

We need to fight for a better food environment.

But an environment that promotes health is also one that enables and entices kids to be active, to use their feet; it requires safe sidewalks, safe streets, parks and public green spaces where a kid can run and play in real life.

Yeah, I know, both these challenges are no small feat.

As to Halloween, a few tips: Make yourselves noticed by carrying a flashlight, walk on a sidewalk or path, and if there are none, face oncoming traffic, cross safely, and stay alert – distracted walking due to cell phones is an epidemic.

Dr. Ayala

Can better hydration help kids think?

How much fluids do you really need?

It’s an old question about one of the most essential components of our diet, yet the answer is surprisingly debatable. Eight glasses a day? To satisfy thirst? So that your urine is clear?

Our body is 60 percent water, and water’s needed for every system and every cell to function. Water keeps our temperature stable, clears waste through our kidneys and urinary system, it pumps blood through our vessels – there’s no function in our body that doesn’t rely on water.

Since water is so critical to bodily functions our body maintains the same blood concentration over wide variations of fluid intake. It’s only when our body is missing significant amounts of water that we’ll see abnormalities in blood tests – and in our ability to function normally.

Dehydration, the state in which water is depleted to the point our body can’t maintain its normal functions is clearly dangerous.

But does being optimally hydrated make a difference? Do smaller variations in fluid intake – the kinds of variations we experience in everyday life and ones that are no way close to clinical dehydration – make a difference?

Although blood samples show little variation in concentration across wide differences of fluid intake, our urine becomes more and more concentrated the less fluid we have – that’s why urine might be a better marker of hydration. Studying urine samples suggests that half the kids in the US have highly concentrated urine, which suggests they’re not drinking much.

Mild fluid deficits, do they matter?

What are the health implications of milder fluid deficits?

A few studies suggest that mild dehydration affects short-term memory in school-aged kids, and on the other hand, when kids are given plenty of water, their memory and attention improves.

A new study, led by Naiman Khan and published in the Journal of Nutrition tests the effect of hydration on cognitive performance. 75 kids aged 9-11 years from Illinois were tested in three conditions for 4 days each: They were drinking as usual (no intervention), were prescribed low water intake (16 oz. a day or about 2 glasses), or high water intake (84 oz. a day or about 10 glasses). On the fourth day of each condition urine was collected to measure its concentration and cognitive tests were performed to assess performance, thought flexibility and inhibition.

And the results: As expected, urine got less concentrated the more fluids the kids took in. Better hydration, benefited kids' working memory and cognitive flexibility according to the the mental tests.

These findings are consistent with findings from other studies that show better hydration improved exercise ability and cognitive flexibility.

Going back to the data that shows that half the kids have concentrated urine signifying insufficient hydration, this study suggests that increasing fluids may be a simple way to help kids think a little better.

Just add water

Our brain is even more water than the rest of our body: it’s 70 percent water. Missing some of it may affect mood, thinking, memory and overall health.

Mood and attentiveness decline first, and while mild changes in body fluids certainly don’t put kids in danger of dropping blood pressure or shutting off their kidneys, proper hydration can help kids perform best at school.

Giving kids access to clean and safe drinking water – safe water fountains in every school! – and prompting them to drink is a really simple way to make sure studying’s a little bit easier and happier.

Optimal hydration may improve overall wellbeing and clarity of mind, and can be a cost- and calorie-free mental boost.

Hydration tips:

How much: 8 (glasses-a-day) isn’t a magic number – so no need to keep count – but is pretty good approximation for an average person in average conditions. The Institute of Medicine (IOM) doesn’t set exact intakes, but recommends about 91 ounces of total water a day for women, and 125 ounces daily for men – and no upper limit for water. Eight glasses is about 64 ounces, add to that the water in food, and you’re not far off from the IOM recommendations. Water needs depend, of course, on activity level, outdoor temperature etc.

What counts: All fluids count, including coffee, tea, soup and the plenty-of water in fruits and veggies.

Assessing hydration: One should rarely feel thirsty, and your urine should be almost colorless. 

Drink More: Provided you’re healthy, your kidneys know how to take care of your fluid levels. Drinking too little can lead to headaches, dehydration, constipation and maybe crankiness, while extra fluids are simply excreted through your urine – it’s difficult to overdrink. Only in unusual circumstances – such as extreme endurance exertion while overdrinking water – can drinking too much water become a problem for healthy people.

Dr. Ayala

 

Full disclosure: I co-founded Herbal Water, which makes organic herb-infused waters that have zero calories and no sugar or artificial ingredients. I’m also a pediatrician and have been promoting good nutrition and healthy lifestyle for many years.