Your Own Data About Nutrition

Thinking About a Personal Health Record - Part II

Short Summary

In Part I, I conceptually divided modern American food into three eras:

1) Food as Fuel (~1890s -1945): Scientists worked on the question of how many calories a man or woman needs to do a day’s work.

2) Food as a Consumer Product (~1950 - 2005): Two forces – industrial food processing and consumer marketing – produced the unhealthy human of the late 20th century.

3) Food as an Ideological and Tribal Battleground (2007 – present): Our attention and clicks are the consumer product.

In Part II, I’m asking: Would some of us be able to stay healthier if we had access to more and better data about ourselves in a highly detailed Personal Health Record (PHR)? And if it existed, who should own that data?

To explore these questions, I’m starting with some very simple examples of nutritional data that anyone can record for themselves.

What Is A Personal Health Record?

In practice, the idea of a Personal Health Record (PHR) has described two rather different things:

1. A tethered PHR. This is the site that allows you to peek at your doctor’s notes or the hospital records — it is a portal into the Electronic Medical Record (EMR.) To be clear, you can see (parts of) it but you don’t control it. What’s more, it is almost exclusively about your interactions with the healthcare system, so it has a record of your colonoscopy. But because you don’t own this PHR data, it probably doesn’t meet your needs. Does it remind you about the next colonoscopy due in five or ten years? Does it include a quick way to check your last tetanus shot? It has your medical “problem list” and diagnoses, but it does not know what you ate yesterday, and probably doesn’t even know that you have been a vegetarian for the last five years. This is not the kind of PHR I am talking about.

2. A standalone PHR for storing the medical records that you collect for yourself, and maybe integrating with the records of healthcare systems. Some attempts at commercializing software for this idea have come and gone, but for the most part it is still a laborious process. I’ve recently pointed out why it might be good to keep your vaccine records on file. And it can help to have all these records if you go somewhere for a second opinion. But most medical records are about sickness, and are not terribly useful for improving your health, even if you are trying to become a masterful manager of a chronic condition like high blood pressure or diabetes. This kind of PHR is only tangentially what I am talking about.

A Different Kind of Personal Health Record

We probably agree that there are lots of things that influence our health besides what’s in those old doctor notes, hospital records, and X-ray reports. Diet and nutrition is one, and that’s where I’m starting. But plenty of people track data for lots of other things about their bodies. Many gym people, for example, have a notebook logging every strength training session; it’s how they keep track of progress. Some endurance athletes log their diet, sleep, and every training run as they get ready for a marathon.

Whatever your health goals, having the data could help. In my practice as a cardiologist, some of the people who lived the longest, healthiest lives seemed to do it by engineering their own bodies, carefully tracking inputs and outputs, using self-experimentation and refining the results to optimize their own diet, exercise, and lifestyle. These patients who came with their data notebook taught me a lot. Now, some people take their commitment to a “Quantified Self” too far, allowing this useful idea to become a crippling obsession. So if you can avoid that, please, let’s consider what a truly Personal Health Record might look like if you wanted to take a more self-reliant approach to curating your own health.

Maybe Owning Your Health Means Owning Your Data

Nutrition Data - Just Because It’s Digital Doesn’t Mean It’s Right

During World War I, Americans at home experienced intermittent shortages and worried about our soldiers in Europe getting enough food. It’s been said that calorie counting began in 1917; Dr. Lulu Hunt Peters, a physician with a newspaper column and a bestselling book, advised women to keep a diet diary and to count calories, becoming thin as a patriotic way to make more food available for the soldiers “Over There.” She promoted “Anti-Kaiser” groups with the slogan “Watch Your Weight,” precursors of mutual support programs like Weight Watchers.

Don’t let the physics freak you out — but calories are a measure of energy. In physics, energy is the ability to do work. And work is force times distance, so when you lift a 20 pound weight, 2 feet off the floor, you did 40 foot-pounds of work. That’s the same amount of energy as about 0.013 nutritional calories — less than one grain of rice. Of course, you are not a perfectly efficient machine for converting rice into weightlifting, and you are always burning energy even when you are perfectly still. Nonetheless, many people, including me, have tried self-experiments at matching their calories in and calories out.

You might think it will be easy because today there are applications that allow you to log everything you eat, and there are wearable devices that will give you a daily report of your energy expenditure, showing that it goes up when you exercise. With access to data for calories in and calories out, it’s reasonable to wonder whether these digital tools could teach some people to balance what they eat with what they burn, matching calories to maintain weight, or programming a calorie deficit to lose weight, a calorie excess to gain weight. It’s rarely so simple, though. To start with, those digital calorie counts don’t come close to the accuracy that W.O. Atwater achieved in the 1890s and 1900s with his laboratory calorimeters. Here’s why:

Figure 1: Sources of inaccuracy estimating energy balance:

Calculating energy burn from heart rate alone is a pretty poor estimate, and your wearable device uses a “black box” algorithm that the company doesn’t share or validate.

Basal metabolic rate (BMR) is the rate of energy consumption when you are doing nothing. Formulas that estimate BMR based on your height, weight, and gender completely miss that some people run hot and others run cold, and that your basal metabolism can even change from day to day.

Food is a variable biological material; not all apples have the same nutrition content.

Accurate food portion measurement is difficult unless you live in a lab and only eat your science experiments. Especially with fats and oils, a little more or less can make a huge difference in the calorie count.

Food labels are imprecise or wrong, and the true nutritional value of the food in the package may change anyway depending on how you prepare it.

As Atwater knew, it’s not what you eat – it’s what you absorb. Eat some corn and check the toilet tomorrow; not all the food you eat is fully digested.

Even if you do manage to overcome these sources of inaccuracy and individual variability, it is hard for most people to program weight gain or loss by adjusting their CI/CO (calories in / calories out.) People are not simple machines nor lab rats, and human food behavior is affected by emotion, the psychological regulation of appetite, habits and external forces in conjunction with the food environment.

Your Nutrition Record

So should you just forget about the idea of personal nutrition records? I don’t think so. Bearing in mind the imprecise nature of nutrition data out here in the real world, there is still value in a diet diary if you want to understand your own health. What would you record? It depends entirely on what you want to achieve — but here are a few examples of ways that self-curated data has worked for my patients.

• Understand your current diet with a one week diary. What are you eating? Do you know your average macronutrient ratio of proteins, carbohydrates, and fats? How much sugar are you eating? How much fiber? How much sodium? While it’s hard to get the numbers precisely correct, you can almost certainly learn something by using a diet-tracker for just a week. You could use a nifty little application that lets you simply take a picture of your plate and automatically database its nutrition data. (A cool idea whose teenage inventor/founder didn’t get into any of his top choice colleges.) Or you could simply write down what you eat in a notebook, like the great American nutritionist Benjamin Franklin did.

  Monday—Din’d at Club—Beef

  Tuesday—at Mr. Foxcrofts—Fish

  Wednesday—Dolly’s Beefstake. Felt Symptoms of Cold Fullness

  Thursday—Mr. Walker’s—Beef. Predicted it

  Friday at home Mutton. Little Soreness of Throat

  Saturday Club Veal. very bad at Night Wine Whey

  Sunday—no Dinner continue bad

  Monday morn. Had a good Night, am better

  U[rine] has deposited a reddish fine Sand.

  Benjamin Franklin’s “Notes on a Week’s Diet and Poor Health, [between 12 June 1769, and 30 July 1770].” Founders Online, National Archives.

  Franklin understood that his diet affected his gout — and in later life his urinary bladder stone.

• Record simple self-experiments. Maybe you’ve decided to try something — adding more fiber, or changing to a low carbohydrate diet. Maybe, like 10-20% of Americans, you’re trying intermittent fasting or time-restricted eating. How will you know whether this is working for you? For some people, a change in their weight or fitting into a tight pair of pants is their outcome of interest. But there are other, meaningful health measurements you could assess, such as…

• Look at the influence of your diet on biomarkers. Sure, it would be great if your doctor would coach you through this, give you the instructions, order the tests, and interpret them for you. But honestly — they probably don’t, because it’s just not in the model of regular medical care. In most states, though, some form of Direct Access Laboratory Testing is available; you can order your own blood tests, go to the lab, get blood drawn, and get the results. So you try a diet for a month, and find that your cholesterol, triglycerides, and hemoglobin A1c have all gone down — suggesting improved metabolic health. You might have just learned something useful for yourself. Maybe you need a little help understanding what biomarkers to track, and why. Stay tuned, I’m gonna cover that!

• Track your nutritional and metabolic profile over years or decades. To do this well does require a bit of understanding about how human physiology works. You can wish that someone was doing this for you — but honestly, the hospital portal and most primary doctors just are not set up to monitor your metabolism over decades. If anyone has the incentives to optimize your health — it’s you.

It’s Your Data

If you do care to keep a PHR, all you really need is a notebook, and it can be as simple or as detailed as you want. A few dedicated people with apps or spreadsheets will record every bite they eat. Others will simply note that for a period of time on a calendar, they tried to follow some diet plan or another. Either way, just documenting it can add a mindful awareness of nutrition. Being slightly intentional with your data can allow you to recognize what works for you.

To be your own scientist, you might want to add some results. Maybe you want to record your weight and waist circumference, and see if a new diet approach seems to help move towards your goals. If this is an unpleasant thing for you to think about, then you don’t have to! It’s your notebook! It’s private.

Figure 2: Observations you collect over time can reveal trends and opportunities to improve your own health. OK, you may not understand HbA1c yet, but it’s just not that complicated! It is a simple blood test that indicates your average blood sugar over the prior couple months. In an upcoming article I will show you how this works.

Use your notebook the way you want, towards the goals you care about. If you eat this way or that way, can it contribute to different results in your blood tests, your sleep, your athletic performance? Probably so. If you’re keeping records, you’ll be a lot more likely to see these trends. Businesses, baseball teams, and armies all know that having their data is a key to improving their performance. A regular paper notebook is a tried and true tool, but one downside is that if it’s lost, it’s lost forever. So maybe think about backing it up with a digital copy from time to time.

One Data Point for One Magnificent Athlete

At the recent World Masters Athletics Indoor Championship in Gainesville Florida, thousands of athletes from age 35 to 95 came from 99 different countries for age group competitions in running, jumping and throwing. Age groups make it work; the 55 year olds are smoking fast compared to the 70 year olds, but slow compared to the 40 year olds. In 15 years, everyone will be slower. Meanwhile when you assemble that many senior athletes, you can’t imagine the number of discussions about diet, training regimens, therapies, supplements, and health.

Part I of this two part article started with food as fuel for work. At the masters championship meet, everyone needed fuel. Some senior athletes think a lot about their nutrition, while others seem to have found what works for them and don’t worry about it much any more. Some are committed to a particular nutritional ideology but others are actively experimenting on themselves to see what happens when they make a dietary adjustment. Tracking their own nutrition and training data with notebooks, apps, and devices, some are using an engineering approach to try to run a little faster, jump a little higher.

If you want to be able to do stuff like this when you’re 90, you’ll need good genes and other kinds of luck, but you’ll also need to put in the work. Train hard. Eat the good food that works for you. Don’t skip leg day.

Photo: Rob Jerome.

Figure 3: The great Flo Meiler, age 90. At the recent Indoor World Championship meet, she established a new world record for pole vault for women in the 90-94 age group. If you’re wondering what Flo eats -- I can tell you that when I asked her, it was a turkey sandwich and some homemade banana bread.

Keep reading the series on Personal Health Data. Part III explores how you might use biomarker data to monitor and optimize your metabolic health.