Wildly inconsistent nutritional information from USA Swimming

USA Swimming offers lots of odd, out-dated, and ill-informed nutritional advice to young swimmers. This series of posts are offered as a corrective.

Moving on to “Tips for Consistent Nutrition” – By Chris Rosenbloom, PhD, RDN, CSSD (Tuesday, March 21, 2017)

The author makes the important point that competitive swimmers need to focus on ‘eating to fuel training and competition every day.’ Absolutely.

And then the author steers into a ditch.

“Your training will not be helped if you are under- or over-fueled.”

We know what ‘under-fueled’ means. But what is ‘over-fueled’? Is the author saying not to add fat tissue (fat = fuel) or is the author giving hilariously obvious advice like ‘don’t walk up to the blocks with a stomach full of fettuccine alfredo?’ 

…too much food can divert blood from working muscles to the gut for digestion.

The latter. Got it.

Plan to eat mini-meals or snacks before a long practice and replenish muscle fuel and fluids after practice. A slice of turkey on a mini-bagel, a Clementine tangerine, and water may be just the thing to get you through a grueling pool and land training session.

That is useful advice.

A carton of low-fat chocolate milk after practice can provide key amino acids for muscle repair, carbohydrates for muscle glycogen synthesis, and fluids.

Here we go. Ok, why “low-fat?” Higher fat milk has more energy to help the athlete perform. These odd little side-comments suggesting there is some reason to avoid fat are really counter-productive.

Consistent Mindset: Do you think of nutrition as something that your parents nag you about? Or, do you take responsibility and seek healthful foods and beverages throughout the day?

Not bad, tells swimmers to take charge of eating more.

Healthy food doesn’t have to mean yucky! Even at your favorite quick service restaurants, healthy options abound.

Ignoring the author’s decision to use the word ‘yucky’, telling swimmers to seek ‘healthy’ options at fast food restaurants is silly. They need to know that quantity comes first, and if fast food is the only thing available then just eat it.

And stop it with the ‘healthy food.’ People are healthy (or not), but calling some foods ‘healthy’ is creepy and counter-productive when your audience is young athletes. Their primary nutritional problem is that it is very hard for them to eat enough food to fuel their training, performance, growth, and normal biological functions. Calling some foods ‘healthy’ implies that other foods are ‘not healthy.’ Young endurance athletes need to eat a lot of every type of food. Fear-mongering about supposedly unhealthy foods is harmful.

It is up to you to think about food as something that can elevate your swimming, and taste good at the same time.

That’s excellent advice.

Parents and coaches can guide a swimmer to healthy foods, but only you can eat the foods to get the benefits.

Wait, why is the author passing the buck to parents? Your job is to give the athletes simple, good advice. Most parents have no clue what the athletes need to eat, and woe to any young athlete who tries to follow the same ‘diet’ as their parents.

Eating a variety of foods: fruits, vegetables, whole grains, healthy fats, and lean proteins, contribute nutrients that feed your brain, as well as your muscles.

Brains run on glucose. Fruit: no glucose. Most vegetables: no glucose. Whole grains: less glucose per ounce than refined grains. ‘Healthy fats:’ no glucose. ‘Lean proteins:’ no glucose (unless broken down and repurposed – it is at best an inefficient way to get glucose).

But the really bad advice concerns fiber. The first three items on the list are high fiber foods. Fiber is implicated in low energy availability and a host of serious metabolic problems for athletes, especially female endurance athletes. Adolescent swimmers need less fiber, not more. As for ‘lean meats,’ increasing the fat content of your diet, including fat from meat, is associated with greater energy availability, athletic performance, and overall health.

Lean meats and fiber are for middle-aged office workers on diets. Adolescent athletes need dense carbohydrate sources and complete proteins with plenty of fat.

Try eating 3 meals and 3 snacks every day during your hardest training periods and take note of how you feel. My bet is you will feel better, stronger, and more energized than when you are eating less food.

Good advice. Eat more and more often.

…there are times when bars or chews or shakes can add needed calories. 

Yes, sometimes you have to go with Gu packets or Gatorade or whatever because that’s just how it is.

Look for wholesome ingredients in these foods: whole grain carbohydrates, naturally occurring sugars from fruit or milk, and healthy fats from nuts or unsaturated oils.

That’s just nonsense.  If the goal is to get extra carbohydrate from a bar, avoid whole grain. Too much fiber. It makes you fuller without providing energy. Athletes need more, not less, energy. And forget the myth about ‘swings in blood sugar’. The 2016 ACSM consensus statement finds no evidence that a food’s glycemic index impacts athletic performance.

Also, there is no evidence that fruit sugar (fructose) is a better energy source or somehow more ‘wholesome’ than refined glucose or table sugar (half refined fructose, half refined glucose). So why would an athlete want chews made from fructose? I have no idea, and I doubt the author does either.

Posted in Uncategorized | Leave a comment

Do young athletes risk their future health when they eat saturated fat?

But wait! Don’t the origins of cardiovascular disease begin at an early age and progress into adulthood, and isn’t elevated dietary fat intake associated with the development of cardiovascular disease?

Let’s take a look at some typical research in this field:

Coronary risk factors measured in children and young adults are associated with the early development of coronary artery calcification. Increased body mass index measured during childhood and young adult life and increased blood pressure and decreased HDL cholesterol levels measured during young adult life are associated with the presence of coronary artery calcification in young adults.

What these studies find is that overweight kids with high blood pressure and cholesterol profiles associated with high carbohydrate consumption (“low HDL” is a bad thing because HDL is considered the ‘good cholesterol’) tend to have heart disease as adults. 

Keep in mind, fat consumption (saturated and unsaturated) raises HDL (the good cholesterol).

We are talking about sick kids turning into sick adults. And they are probably eating too much carbohydrate.

It used to be believed that these people developed obesity, heart disease, high blood pressure, and diabetes because they ate too much fat. But  many groups eat lots of fat and didn’t have high rates of chronic diseases, so the hypothesis was revised to suggest that these kids were eating too much saturated fat. And maybe not exercising enough. Further evidence has done that hypothesis no favors, and now the concern is that maybe these folks are eating too much carbohydrate (yes, the thing they were told to eat MORE of all along).

No studies find that healthy teenage athletes – even those who eat like Katie Ledecky or Michael Phelps – are more likely to develop heart disease as adults.

In fact, studies find endurance athletes do well when placed on high fat diets (50% of total calories), that these diets ‘did not result in adverse changes to the plasma lipoprotein profiles‘ (meaning their cholesterol was fine), and did ‘not increase body weight or adiposity‘, which is a research-y way to say they didn’t get heavier or fatter.

Rachel Brown was a member of both research teams and would go on to become an important researcher on the subject of Low Energy Availability (LEA) in athletes, a precursor to the female athlete triad, a dangerous syndrome caused by athletes undereating compared to the demands of exercise and normal physiological needs. 

The real danger for teenage athletes, especially endurance athletes and especially women, is Low Energy Availability (LEA) which has significant adverse health effects on athletes (and not insignificantly, hurts performance too). 

One of the better ways to combat LEA: eat more fat.

Diets at the upper end of what is recommended by the American College of Sports Medicine – 30% – are associated with top performance and reduction in symptoms of LEA.

 


 

Posted in Uncategorized | Leave a comment

USA Swimming gives some bad nutritional advice on dietary fat

USA Swimming offers lots of odd, out-dated, and ill-informed nutritional advice to young swimmers. This series of posts are offered as a corrective.

Today we consider “Clearing the Confusion on Fat” written by Chris Rosenbloom Ph.D., RDN, CSSD. Let’s jump right in.

First, the author makes a big factual error. The author claims:

Saturated fats, like coconut oil, butter, and palm oil, raise risk of CVD.

Eh, no. (By the way, the author defines CVD (cardiovascular disease) as “heart disease, blood vessel disease like high blood pressure, peripheral vascular diseases, and stroke”.)

First, saturated fat does NOT raise the risk of stroke. Even researchers who are wary of dietary saturated fat note there is no link to stroke. Here’s a typical quote:

…the available evidence suggests that SAFA [saturated fatty acid] reduction has little, if any, direct effect on stroke risk, but that the consumption of SAFA-rich dairy foods may be associated with a lower risk of ischemic stroke. 

You catch that last part? Dietary saturated fat may reduce the risk of stroke. Surprise!

Yes, many public health officials express concern about a link between dietary saturated fat and increased risk of heart disease. There are some researchers who claim there is cause for reducing saturated fat consumption. But read carefully the reports they cite. Note the population being discussed (generally middle-aged non-athletes) and the magnitude of the effect (slight).

For instance, a 2015 Cochrane meta-analysis did find a small benefit associated with swapping out some saturated fat and replacing it with polyunsaturated fats, but the benefit was limited to those with bad cholesterol profiles. It was only the sicker, older study participants that received the slightest benefit, and only on one indicator – the frequency of heart disease. By the way, reducing saturated fat intake did not reduce the rate of DEATH from heart disease. That’s confusing. But typical of a larger pattern in dietary studies where ‘small effect’ and ‘no effect’ can seem indistinguishable.

Others look at the same studies and see no benefit to reducing saturated fat intake. Their research suggests that dietary saturated fat is harmless.

Finally, for teenage female athletes, there’s reason to believe that a higher level of saturated fat intake is beneficial.

Perhaps the author of this USA Swimming article (Rosenbloom) has excellent reason to disagree with this body of research. If so, the author needs to say that. Or avoid the subject entirely.

Second, the author needs to remember the audience.

Screen Shot 2018-12-02 at 11.47.07 AMThis is nutritional advice for the athletes of USA Swimming. In 2016, there were 336,036 year-round swimmers in USA Swimming. More than 96% of these swimmers were 18 or younger (and 56% are female).

There is currently no evidence that endurance-trained athletes under the age of 18 suffer from cardiovascular disease brought on by consumption of dietary fats.

Young athletes do (rarely but tragically) suffer from, and die of, cardiovascular diseases. Hypertrophic cardiomyopathy is the most common of the (still very uncommon) genetic heart abnormalities that afflict young athletes. Here’s the thing though. Hypertrophic cardiomyopathy is a genetic condition. It is not caused by eating coconut oil.

You want to clear the confusion on fat for young swimmers? Start by telling them:

  • Don’t worry about it.
  • Right now, researchers disagree about the health value of various fats – saturated, monounsaturated, polyunsaturated.
  • Most things you’ll hear about dietary fats and health are wrong, so ignore it.
  • There is no evidence that any dietary fats pose a health risk to fit young athletes.
  • You may want to review current nutritional guidelines when you are in your 20s.

Parsing the different types of fats based on saturation, as the author does, and saying that some fats need to be avoided might (or might not) be useful for sedentary middle-aged office workers.

For the audience of young swimmers, this message on dietary fat is a needless distraction at best. And it potentially causes confusion, and fear, about food in general.

For most teen and preteen athletes, their primary nutritional challenge is to simply eat more food. They have limited time (and appetite) to consume the food needed to grow to their full potential and compete in the arena of their choosing. Their parents are unlikely to have the time to do independent nutritional research. These families need good, simple advice. You run the risk of doing real harm to these athletes when you tell them (and their parents) that consuming dietary fat is potentially dangerous and must be done with great caution. You especially put at risk your largest and most vulnerable audience – those young female athletes who should be eating more fat.

More on that when we discuss the (serious and dangerous) female athlete triad.


The standard disclaimer: I am a parent of a serious teen swimmer. I am not a physician. I do not hold any certification in the field of nutrition. I am not a registered dietician. I read research publications and nutrition reports, but I do not do any independent research. Basically, I am lay-person, motivated by my concern for the well-being of my kid. For me to be able to tell that nutritional advice is bad, it has to be really bad.

 

Posted in nutrition | Leave a comment

1,400 Days and 750,000+ (extra) calories: Math, growth, and varsity baseball (part 2)

This is probably a good time to reiterate that we claim no expertise as nutritionists or dieticians. These posts are based on a lay reading of readily available information, plus a spreadsheet. Math is, after all, the great equalizer.

Where did we come up with that number? Does a 13-year-old athlete weighing 130 pounds really need to eat 750,000+ extra calories to grow to a 17-year-old athlete weighing 175 pounds?

Basically, yeah.

Look at the chart below. Ike adds about 1 pound per month every month until the summer before his senior year. Each pound he adds increases his maintenance caloric needs by 20 calories per day, or 600 calories per 30-day month. By the time he adds 10 pounds, he needs to eat over 6,000 more calories per month just to maintain that weight.

The caloric surplus needed for GROWTH is calculated separately, and conservatively. He probably needs about 2,800 calories to gain a pound of muscle and about 3,500 calories to gain a pound of fat. So each pound added is calculated as requiring about 3,000 excess calories. Add it all up and Ike needs to add 764,520 calories to his current baseline diet over the next 1,400 days.

Bon appetit, Ike!

Weight Maintain Days Monthly surplus Age Date
130 2,600 31 0 13.76 Oct-18
131 2,620 61 600 13.84 Nov-18
132 2,640 92 1240 13.92 Dec-18
133 2,660 123 1860 14.01 Jan-19
134 2,680 151 2240 14.08 Feb-19
135 2,700 182 3100 14.17 Mar-19
136 2,720 212 3600 14.25 Apr-19
137 2,740 243 4340 14.34 May-19
138 2,760 273 4800 14.42 Jun-19
139 2,780 304 5580 14.50 Jul-19
140 2,800 335 6200 14.59 Aug-19
141 2,820 365 6600 14.67 Sep-19
142 2,840 396 7440 14.76 Oct-19
143 2,860 426 7800 14.84 Nov-19
144 2,880 457 8680 14.92 Dec-19
145 2,900 488 9300 15.01 Jan-20
146 2,920 516 8960 15.08 Feb-20
147 2,940 547 10540 15.17 Mar-20
148 2,960 577 10800 15.25 Apr-20
149 2,980 608 11780 15.34 May-20
150 3,000 638 12000 15.42 Jun-20
151 3,020 669 13020 15.50 Jul-20
152 3,040 700 13640 15.59 Aug-20
153 3,060 730 13800 15.67 Sep-20
154 3,080 761 14880 15.76 Oct-20
155 3,100 791 15000 15.84 Nov-20
156 3,120 822 16120 15.92 Dec-20
157 3,140 853 16740 16.01 Jan-21
158 3,160 881 15680 16.08 Feb-21
159 3,180 912 17980 16.17 Mar-21
160 3,200 942 18000 16.25 Apr-21
161 3,220 973 19220 16.34 May-21
162 3,240 1003 19200 16.42 Jun-21
163 3,260 1034 20460 16.50 Jul-21
164 3,280 1065 21080 16.59 Aug-21
165 3,300 1095 21000 16.67 Sep-21
166 3,320 1126 22320 16.76 Oct-21
167 3,340 1156 22200 16.84 Nov-21
168 3,360 1187 23560 16.92 Dec-21
169 3,380 1218 24180 17.01 Jan-22
170 3,400 1246 22400 17.08 Feb-22
171 3,420 1277 25420 17.17 Mar-22
172 3,440 1307 25200 17.25 Apr-22
173 3,460 1338 26660 17.34 May-22
174 3,480 1368 26400 17.42 Jun-22
175 3,500 1399 27900 17.50 Jul-22
Extra Maintenance
629520
Weight Increase (pounds)
135000
764520
Posted in Uncategorized | Leave a comment

1,400 Days, 750,000+ (extra) calories: Math, growth, and varsity baseball (part 1)

Let’s say your 8th grader, ‘Ike’, is a terrific baseball player. At 13 years old, Ike is the youngest player in his league but competes successfully against players who are already playing junior varsity baseball in high school.

Ike is having a lot of fun playing baseball, and it is his goal to keep it going through high school and play varsity baseball as a junior and senior.

Ike is 5’6″ tall and weighs 130 pounds, so his weight is in the 75th percentile for his age. Conservatively, he’s on pace to be 6′ tall by the time he’s a high school senior, and to maintain his 75th percentile weight, he will need to gain about 45 pounds (to around 175 pounds). It turns out that 175 pounds is a fairly typical weight for the current varsity seniors on his high school team.

Right now, Ike eats about 2600 calories per day to maintain his weight. This is fairly standard. Moderately active teenage athletes (training and playing 5-9 hours per week) need to consume about 20 calories per pound to maintain their current weight.

Ike wants to grow at a steady pace over the next 1,400 days or so (that gets him to the middle of the summer before his senior year). How many EXTRA calories does Ike need to eat over the next 1,400 days?

Over 750,000. That’s 750,000+ EXTRA calories, above and beyond what he would consume if he just ate his current 2,600 calories a day for the next 1,400 days.

So is this really a problem, don’t teenage boys just naturally eat a lot? Sure. Hormones drive teenage boys to eat a lot and grow a lot. The average 13-year-old male weighs 100 pounds. The average 17-year-old male weighs 140 pounds (CDC BMI calculator – http://bit.ly/2Ja6YyG).

However, the challenge for teenage athletes is much larger.

First, athletes train. Training requires extra energy. Sedentary people need to consume 12-13 calories per pound of body weight to maintain their current weight. Athletes who train 5-9 hours per week need more like 20 calories per pound of body weight. During periods of very high exertion, it’s more like 25 calories per pound. For maintenance. Not growth. Maintenance.  (Estimated Daily Energy (Calorie) Needs for Competitive Athletes, http://bit.ly/2J6FUQH.)

Second, Ike is not trying to go from 100 pounds to 140 pounds, he is trying to go from 130 pounds to a minimum of 175 pounds. That’s five more pounds and he starts from a much higher baseline, where he is already eating more than the average 13-year-old.

Third, weight loss carries a high risk. As a baseball pitcher, Ike works hard at strengthening the muscles in his lower arm, shoulders, and hips. If Ike does not eat enough and does not carry enough body fat, he is vulnerable to catabolism – the body’s irritating habit of burning muscle for fuel when other sources are not available. If gaining muscle to support vulnerable joints lowers injury risk, then losing some of this muscle is highly undesirable, even dangerous.

In part II, where we come up with that number of ‘750,000+ excess calories.’

Posted in Uncategorized | Leave a comment

Nutrition for teenage athletes

Disclaimer: I am not a physician, metabolic researcher, or ‘nutritionist’ and make no claim to hold any certification in the field of human nutrition.

I am a concerned parent raising two teenage athletes – one a swimmer, the other a baseball player – and I find that nearly all the expert nutritional advice circulated for teenage athletes appears to be written for sedentary adults.

…I find that nearly all the expert nutritional advice circulated for teenage athletes appears to be written for sedentary adults.

My goal is to discuss some observations and present the findings of my own research into published medical findings. I take seriously what elite athletes say when they speak candidly about food and I want to convey what some elite coaches say about the nutritional needs of their athletes when the topic is performance, not nutrition.

This last part is important. When speaking about performance and athletic goals, experienced athletes and coaches say some astonishing things about what and how much they eat. This information does not regularly make its way into the advice offered by nutritional experts.

When speaking about performance and athletic goals, experienced athletes and coaches say some astonishing things about what and how much they eat. 

I beg your indulgence in my use of pronouns. My son plays baseball. My daughter swims. I use ‘he’ and ‘she’ respectively when I write these posts because I am thinking about my own kids. I am not implying anything about the relationship between specific gender identifications and specific sports, nor do I think I have anything significant to say about other people’s gender identifications or their choice of athletic or recreational pursuits. Whoever you are and whatever sport you choose to do (or not do), good for you and good luck.

One post will look at the number of extra calories a hypothetical male teenage baseball player will consume to grow from 130 pounds in 8th grade to 175 pounds when he walks onto the field as a varsity player in his senior year. Another post will look at the energy needs of a hypothetical female teenage competitive swimmer looking to gain strength and drop time. There may be other posts as well.

As always, thanks for reading.

Posted in Uncategorized | Leave a comment

Jimmy Carter’s spurious evidence for the crisis of confidence

From wikipedia:

On July 15, 1979, Carter gave a nationally televised address in which he identified what he believed to be a “crisis of confidence” among the American people. This came to be known as his “malaise” speech, although Carter never used the word in the speech.

This ‘malaise speech’ is rather famous, and there is some controversy over its reception and effect. Some look back on the speech and see it as typical of some awful traits in Carter – weakness, and a scowling disdain for his fellow Americans. Others suggest the speech was well received and nicely captured a mindset, more broadly accepted now, that we are in a state of self-inflicted decline (environmental, cultural, political and economic), but we may find a degree of moral redemption by gracefully managing this irreversible downward slide.

I don’t care about any of that. I care about one paragraph from the speech:

The symptoms of this crisis of the American spirit are all around us. For the first time in the history of our country a majority of our people believe that the next five years will be worse than the past five years. Two-thirds of our people do not even vote. The productivity of American workers is actually dropping, and the willingness of Americans to save for the future has fallen below that of all other people in the Western world.

Sentence 2: For the first time in the history of our country a majority of our people believe that the next five years will be worse than the past five years. 

Gallup does regular polling on that question. In August 1979, 75% of Americans believed things would be BETTER over the next 5 years. At no point in the 1970s did that mark fall below 70%.

Sentence 3: Two-thirds of our people do not even vote. 

In 1976, 55% of the voting-age population voted in the presidential election. Voter turnout in the midterm election was 39.1%. That is low turnout, but not especially for midterm elections. It beats 1926 (32.9%) and 1946 (38.8%). 1946. Are we to believe that Americans were suffering from a crisis of the American spirit in the prosperous years following World War II as our nation rose to the status of global superpower?

Sentence 4 (a): The productivity of American workers is actually dropping…

Labor productivity was going down during this period, but that wasn’t a new phenomenon (productivity cycles up and down over the decades), and Carter missed the point anyway. The problem was with wages, not productivity. For example, labor productivity declined sharply in the mid-1950s, but compensation relative to productivity rose significantly. So people weren’t working as hard and were getting paid better. That didn’t feel like a crisis.

The troubling decline in the late 1970s was actually in ‘Real Hourly Compensation’. Productivity and compensation do not march in lockstep (look at the 1950s), so if Carter was implying that American workers were suffering economically because they were less productive, then he was wrong. And in a mean sort of way.

Sentence 4 (b): …and the willingness of Americans to save for the future has fallen below that of all other people in the Western world.

Bracketing the odd choice of the word ‘willingness’ (what with the decline in real hourly compensation), the statement is just not true. In the late 1970s, Norway’s household savings rate was far below the U.S. household savings rate. Same with Sweden, and probably Iceland and Finland.

You can’t refute subjective arguments and moral reasoning. They are not meant to be testable. But the evidence presented to bolster that reasoning can be tested. And then we each have to decide what it means about the larger argument when the evidence presented is shown to be garbage.

 

 

Posted in Uncategorized | Leave a comment