Busted! Nutrition Myths, Part 3: Do you need eight glasses of water a day? Does the timing of meals matter? Does the alkaline diet work?

By Susan March Burke

#1: Does everyone really need eight glasses of water a day?

This myth has been dismissed repeatedly over the years, most recently in the New York Times where Dr. Aaron E. Carroll (a pediatrician and a researcher) explained the origin. He noted that the original 1945 Food and Nutrition Board recommendation for about 2.5 liters (about 10.5 cups) per day was not for “water” per se – but for fluid – much of which is contained in foods.

Everyone doesn’t need the same amount of calories, so why would everyone need to consume the identical amount of water? How much water is enough depends on you, and your environment.

All our biochemical reactions are dependent on water. Water is the key ingredient that keeps our bodies regular, to form and remove waste by the kidneys through urine. More than half of our body weight is water, which means that your weight can fluctuate significantly, especially if we’re exercising in heat and humidity, and losing water through sweat (our built-in air conditioning system). Our body requires water to maintain blood volume, which in turn delivers oxygen and nutrients throughout the body.

Even mild dehydration can drain your energy and make you tired. Pay attention to your thirst, and drink as soon as you’re thirsty. The color of your urine will tell you if you’re hydrated enough; a light, pale color indicates good hydration whereas deep, dark yellow can mean you need to drink more.

People who exercise for more than an hour and at high altitude, as well as pregnant and breastfeeding women, need more fluid. As we age our thirst recognition diminishes, and we need to be vigilant and remind ourselves to pay attention to getting enough fluids throughout the day.

Almost all fluids count to fulfill your daily water requirement. MayoClinic.org says what we eat provides about 20% of our fluid intake – if you eat lots of fruits and vegetables it could be more and some produce, such as watermelon and spinach, are 90% or more water by weight.

Coffee and tea count as fluid; the myth that they’re dehydrating has been debunked. However, caffeinated beverages should be limited so you don’t exceed 400 mg daily (3 c coffee/4 c black tea). Herbal teas are good. Fruit and vegetable juices are high in calories and low in fiber (unless you’re using a machine that blenderizes instead of disposes of fiber). Broths and soups can be high in sodium and/or MSG – read the label. Milk, fortified soy and/or rice beverages are mostly water – buy unsweetened.

How much is enough? How much is too much? A simple equation to help adults figure their fluid needs is that for every pound of body weight, you need about half an ounce of fluid intake per day. For instance, if you weigh 185 lbs., simply multiply 185 by 0.5 to estimate your daily fluid needs in ounces, then divide by eight to estimate your fluid needs in cups per day, rounding up to the nearest full cup. For example: 185 x 0.5 = 92.5 ounces; 93 ounces divided by 8 = 11.6 cups of fluid per day, or rounded up to 12 cups.

Can you drink too much water? Hell yes! We hear about it all too often, from high school athletes to marathon runners collapsing from an acute electrolyte imbalance from over-hydrating. According to an article published in MedicalDaily.com, “Athletes are at the greatest risk of drinking to the point of exercise-associated hyponatremia, which occurs when the kidneys become flooded by large quantities of water, unable to process the liquid efficiently. The sodium levels in the human body aren’t able to balance the amount of water, eventually leading to swelling cells and — in severe cases — death.”

I know this is going off on a bit of a tangent, but please bear with me. Is it possible that the beverage industry is at least partly responsible for perpetuating this “more water” myth? An article in the HuffPost.com reports that internationally, 50 billion water bottles are consumed yearly, 30 billion in the USA alone. To fill one bottle of water, it takes three times that amount because of the chemical production of plastics.

Imagine that plastic water bottle with 25% of it filled with gasoline. It takes 50 million barrels of oil to pump, process, transport and refrigerate bottled water yearly – and 80% of water bottles end up in landfills, only two in 10 are recycled.

Plastic can leach into the water it holds. Hormone-disrupting phthalates are typically present in bottled water after as little as 10 weeks of storage, and the leaching process accelerates if the bottles have been left in the sun.

Cuenca has the best public water in Ecuador and is among the best in South America. Bottled water costs more than 1,000 times tap water. More than 780 million people around the world don’t have access to safe drinking water, so let’s appreciate and use what we have.

#2: Timing of meals isn’t as important as total calories consumed daily

What I love about science is that it advances by correcting, clarifying, and improving existing knowledge. Conventional wisdom held that regardless of the time of day that the calories were consumed, at the end of the day, what influences weight is what you eat – how much you eat – and how much activity you participated in during that day. This supported the “calorie in/calorie out” theory. Today, however, we’ve discovered that it’s much more complicated than that.

Recent studies have confirmed that the timing of meals can potentially have a very important impact on your weight. Food is processed differently at different times of the day, possibly due to body temperature, hormones, how that food is absorbed and digested. For example, eating before sleeping can disturb your sleep rhythm, and play havoc with blood sugar levels. It can also affect your body’s ability to lose weight, and raise the risk of chronic disease.

Those who eat their major meal later in the day lost less weight during a 20-week weight loss program compared to those who ate their main meal earlier (before 3 p.m.), even when their food, activity level and sleep were the same. Another study on healthy, normal-weight women showed that those eating lunch late in the day burned fewer calories while resting and digesting their food than if they ate at 1 p.m.

For many, eating late is unavoidable, but the studies show that that old adage, “eat breakfast like a king, lunch like a prince, and dinner like a pauper” is rooted in truth. Americans are far more likely to have this switched around. The USDA survey, “What we eat in America,” shows that adults eat less then 20% of their calories at breakfast, but almost 35% for dinner”.

And for sure, late-night snacking can mean the difference between a healthy weight and overweight. If you’re reaching for sweet treats late in the day, know that they’re quickly absorbed and stored as fat – they’re also liable to shoot your blood sugar up – and because you’re not active, you don’t have the opportunity to stabilize, setting yourself up for late-night eating.

Instead – prepare to succeed!

Out of site/sight, out of mouth. Keep unwanted sugar-laden junk out of the house, so you’re not tempted. I never say, “eliminate”, I always say, substitute – have something guilt-free to eat if you’re hungry and/or just feeling like a snack. Instead of fat and sugar-laden ice cream, stock fruit in your freezer – frozen grapes that are sweet and fun to suck on; frozen bananas can be whipped into a delicious smoothie with Greek yogurt and a teaspoon of honey. Very satisfying, and nutritious too.

#3: Follow an Alkaline Diet for weight loss and avoiding cancer

As those who regularly read my columns know, my philosophy and experience, supported by science, is that “all diets work” for weight loss. I’ve had this argument many times with my colleagues, who say that diets don’t work, but of course they all do…temporarily.

One ground-breaking study compared four popular diets; very high fat/low carb Dr. Atkins; 40/30/30 Zone (40% carb/30% protein/30% fat); Dr. Dean Ornish (very low fat/mostly healthy plants); and LEARN, a lifestyle modification program – to see which diet produced the most weight loss, and to measure the effect on certain metabolic indicators.

And what happened? All participants lost weight. The Atkins program had the most initial weight loss and all improved blood lipids. But, regardless of the diet, most participants regained some weight after one year, and those who had followed the Atkins diet regained the most.

No surprise there! They proved it again! All diets work. For most people, a “diet” simply means changing what you usually eat and eating fewer calories. Low carb works, low fat works, and very low fat works; but no diet works permanently without permanent lifestyle change. By the end of this study, all the participants had started to regain weight. In fact, there hasn’t been one study that demonstrates that any particular weight loss diet program is better at keeping weight off long-term.

And so it is with the alkaline diet. The myth of this diet has been around for quite awhile, but a client recently sent me an email with the link to a web page where a hunky young man is quaffing a glass of juice with a caption that pronounces that in just five steps, you too can have an alkaline pH, more energy, weight loss, and a lower risk for cancer. The first thing I noticed was the pop-up ad inviting me to purchase his book and his “key” supplements I needed to buy to succeed on the diet.

All foods are “acidic” or “alkaline” depending on its pH value, seven being neutral. But as Dr. David Mirkin, quoted in LiveStrong.com so succinctly said, “All foods are acid in your stomach and alkaline in your intestines. No amount of food can make your stomach less acidic or stop your intestines from neutralizing acid.”

Alkaline foods include most vegetables, but it appears that only a few fruits are on the “include” list; all nuts, seeds, legumes, and root vegetables are “alkaline”. In the “no” zone, are so-called acidic foods which includes red meat, pork, and sugar in any form – honey, dried fruit, jam and jelly – and wheat. But on this “no” list of acid foods are many “healthy” foods like most fish and eggs – and some of the most healthful fruits around, including blueberries, bananas, mango, and orange.

It appears that the “alkaline diet” emphasizes mostly healthy foods – an acidic diet restricts some of the foods that are decidedly unhealthful. However, some of those “no” foods are decidedly on my “yes” list!

So, can it help you lose weight? Sure, just like all diets do. If you cut out the junk, and eat healthy foods, you too can improve your health.

Regarding cancer, The American Institute for Cancer Research says, “What you eat can have a profound affect on your cancer risk, but the acidity or alkalinity of foods is not important. Instead, focus on making dietary choices that can truly affect your risk: Eat a wide variety of vegetables, fruits, whole grains and beans; limit consumption of red and processed meats; enjoy alcohol in moderation, if at all.”

An alkaline diet may help with one condition.  Kidney stones may respond to your diet. If you are prone to, or have a history of, kidney stones, you may need to avoid certain foods, but scientists do not believe that eating any specific food causes stones to form in people who are not susceptible. According to the National Institutes of Health/Diet for Kidney Stone Prevention, by making changes in fluid intake and, depending on the type of kidney stone, dietary changes of sodium, animal protein, calcium, and oxalate, you can lower your risk. However, you need to know the type of kidney stone you’re prone to – calcium oxalate, calcium phosphate, or uric acid – since there are different recommendations for each.  To lessen the possibility of all three, lowering the amount of animal protein consumed and drinking more fluids are recommended. Read more here.

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Susan Burke March, a Cuenca expat, is a Registered and Licensed Dietitian, a Certified Diabetes Educator who specializes in smart solutions for weight loss and diabetes-related weight management. She is the author of Making Weight Control Second Nature: Living Thin Naturally—a fun and informative book intended to liberate serial dieters and make healthy living and weight control both possible and instinctual over the long term. Do you have a food, nutrition or health question? Write to me at SusanTheDietitian@gmail.com