Zac Townsend

It can be hard to read: on the first day of the study, October 2, 2013, I weighed 236.3 lbs and this morning I weighed 178.0

The study

I have been a participant in the One Diet Does Not Fit All: Weight Loss Study. The theory of the study, which makes intuitive sense to me, is that people's bodies and genetic makeup are different and, as a result, that different people would lose weight on different diets. That is, they're trying to "find characteristics that would help determine differential response to weight loss diets."

My study is a follow up to "The A to Z Weight Loss Study" which randomized premenopausal women to one of four diets. In that study, among many other things, "the investigators observed a 3-fold difference in 12-month weight loss for initially overweight women who were determined to have been appropriately matched vs. mismatched to a low carbohydrate (Low Carb) or low fat (Low Fat) diet based on their multi-locus genotype pattern."

Thus my study was born. It started as the Diet X Genotype Study and got NIH funding, and then expanded both in the tests administered to each participant and the number of folks in the study through outside funding (see more in the Wired article Why Are We So Fat? The Multimillion-Dollar Scientific Quest to Find Out).

They're testing as many of us on as many factors as they can to see if some of the those factors correlate with successful weight loss on one of the two randomized diets: low-carb and low-fat. For example, they're sequencing the parts of genome that might predict our success on one diet or the other. Additionally, they figuring out how insulin-resistant we all are (through a Glucose tolerance test, our resting energy expenditure, something about how our fat is stored (I had two fat biopsies), and also information about our microbiome. The outcomes seem pretty simple: weight, waist, and a body composition measurement (DXA scan).

Why I joined the study

I've been overweight for a long as I can remember. Actually, obese, which at my height is anything over 190, and "severely obese" at times, which is 250 and above.

My weight didn't really come up all that much on my mind or with my friends. If anything, it was just the target of my own self-depreciating humor. I got made fun of some in middle school, but that might just be why I am a tough fella.

Adulthood is more explicitly forgiving although perhaps not implicitly forgiving. I do remember having a very candid conversation with my high school math teacher my senior year. I was close to him and had him for three years. He had worked in industry for a long time before retiring to teach us calculus. At some point my self-consciousness about my weight came up and he shared with me that as a one-time manager of people he thought I'd be disadvantaged in life for weighing so much. People would assume things about me that weren't true. I might not get jobs or opportunities I deserved for the subtle biases that being obese brings with it.

I didn't think about that all too often though. I didn't think about it much, since I really had never known anything else. I had always felt like I could do the things I wanted to do without much inhibition. I now know that you do get treated differently if you're thinner and more attractive, something I'm sure I "knew" but wasn't particularly pleasant to think about fifty pounds ago.

Thinking a little bit more about my weight had a weird trigger: James Gandolfini dropped dead at 51 last June. My reaction was oddly personal, since it's not like I'm a big fan or anything. I thought to myself: he's an overweight guy from New Jersey, and I'm an overweight guy from New Jersey. I don't want to die when I'm in my fifties. I suddenly became concerned about my long-term health.

I wasn't sure what to do though.

Around this time, Dan and I were driving a lot between San Francisco and Mountain View while we were going through YC. We had lots of meetings with VCs, meetings with potential bank customers, and meetings with startups to understand their financial problems. Over and over again, I heard a radio advertisement for a Stanford weight loss study. A few times I'd think to myself that I have to remember the URL or Google it. Eventually, after a month or two, I did.

I then got invited to be screened for eligibility. One has to be at least overweight, with relatively stable weight, and be within certain blood pressure and cholesterol bounds. (By the way -- the study is still recruiting) I got through that and then attending a informational, consent, and Institutional Review Board session: these things could happen to you, the diet could be terrible for you that's the point of a randomized experiment, will you consent to the extra tests and to having your blood stored forever.

The support and training

After that all, I was assigned to a particular nutrition class. On the first night, I showed up with almost twenty other people. We were a cohort of sorts. We would all have the same diet. We'd see each other consistently over the year to learn from our nutritionist and to share how it was going. It was some mixture between group therapy and a very basic science class.

For the first eight consecutive weeks we got training and support on the diet. Things like how to do lunch, how to snack, etc. After that the classes tapered: every other week, then every three weeks, then just once a month from the six-month mark to the end of the year. The classes also switched to shared topics across the cohorts like mindless eating, making sense of food labels, sleep and weight loss, etc.

These classes were incredibly important and supportive. Even though people might be on the "right" diet or the "wrong" diet, it always felt like they wanted us to succeed.

The diet

I was randomly assigned to the low-carb diet. For the first eight weeks they'd like you to try to stay below 20 grams of carbs a day. (For folks familiar with Atkins, that's total carbs not net carbs). That's a low amount. I stayed below that number for maybe six months or so, although I've become a little more liberal now introducing things like berries and nuts. I still haven't had grains, bread, rice, potatoes, sugar, etc for a year now.[With few exceptions, see footnote 1]

I find the low carb diet pretty easy to maintain: it's basically vegetables, meat, eggs, cheese, and then pure fats like oil and butter. Thank god for cheese. In particular, I eat out a lot and it's usually pretty easy to manage these restrictions. Many dishes are composed of a carb, a protein, and a vegetable. Almost everywhere I've eaten in the last year they'll substitute more of the vegetable for the carb. I do have to avoid some types of places I've historically loved: pizza, ramen, dumplings, etc, but no one has minded changing locations of get togethers.

I think the low-fat diet is a little harder to manage because you're trying to avoid oil and butter. That's hard to do and eat out. Although, there is an element of resiliency here: maybe if I was on the other diet I'd say that was the easy one.

Sometimes it can be hard for me to know whether it's the diet that made my weight loss. I haven't eaten at Bi-rite Creamery (a famous ice cream shop) or Tartine (a famous bakery) in a year, both of which are minutes walk from my house. That is, importantly, my relationship with food has changed. It's become no less joyful but it has become more deliberate. I think about what I'm eating.

I'm pretty sure I eat less. I eat a lot, more than I need to I think, but I use to go, for example, to an Indian buffet or something like that and eating until I was absolutely stuffed. I've only had that feeling a few times in the last year.

So was it the composition of my food or my changing relationship to eating? The answer is likely both.

The other stuff

Whether or not it was the easy diet, it worked well for me. I've also been particularly fanatical about the diet. I find it easy to have a strict rule-set and then just to follow it without compromise. I like how the diet has limited my choices, particularly as I'm building Standard Treasury. I also think having an oracle -- Stanford, science, whatever you'd like to call it -- is very helpful. I can't break the diet because more is at stake than just my personal well-being.

Most importantly, though, is that I'm at an easy place in my life to do this sort of thing. Some of the other people in my class have spouses who weren't doing the diet and/or kids. It's pretty easy for me to do exactly what I want food wise because I'm not actually beholden to anyone else. It's easy for me to eat protein heavy because the cost of food isn't a concern for me.

I also did not have any naysayers. All of my closest friends, my family, and my colleagues have been incredibly supportive over the year. Some of them have even adopted the diet entirely or almost always follow it when we're together.

There are also compounding returns, cumulative effects, or a virtuous cycle in two senses. The first is the results. I lost ten pounds, people notice. People compliment me. That's feels good. I stick with it. I lose ten more pounds. Etc. At some point the speed at which I was losing weight certainly slowed down, but by that time I had lost a lot of weight. It doesn't happen all the time, but I have pretty constantly seen people over the last year who haven't seen me since before the diet started: and their reactions have only gotten bigger and better over time. That's a big motivator.

The other place I've seen compounding returns is in exercise. Even before the diet, I had exercised pretty consistently, but as I lost weight it became easier to exercise so I would do so more intensely or for a longer time. Just last week, for example, I was in Boston and didn't have access to the gym. I decided to run around the Charles. I don't think I've run a continuous mile in my life: I easily ran three nine-minute-ish miles. Not fantastic. Not world class or anything like that. But also doable. I repeated that three days in a row. In short, I exercise more because it is more fun because it is easier.

Lastly, in class we learned about the National Weight Control Registry: "The NWCR is tracking over 10,000 individuals who have lost significant amounts of weight and kept it off for long periods of time." These folks have some common behaviors. Among them is: tracking their weight, tracking what they eat, eating breakfast, and being active. Of those, I have done everyone but tracking what I eat over time -- I find it a big pain in the ass. The other three habits have been critical to my success though, and I think I'll keep them.

The future

The results of the diet have been good for me. I've lost weight. My blood pressure has stabilized to normal. I'm more energetic. I exercise more. I'm more confident in some parts of my life. It's been good.

I'm still losing a few pounds a month and I'd like to keep that up. The BMI line between "normal" and "overweight" for my height is 155 lb. My doctor has said I shouldn't force that since I'm much wider (in the shoulders) than an average person my height; however, I'd like to stabilize in the 160s. So, another 15 lbs to go to reach my goal. We'll call is 75 lb. from when I started the study. I think it will be pretty easy to get there: mostly just time and keeping up the fanatical devotion.

More importantly, weight maintenance is a big problem for most people, so I'm not celebrating that much or declaring some sort of victory. I doubt that I'll stick with the diet forever as strictly as I have over the last year -- I'd like to eat a chocolate chip cookie again in my life -- but my relationship with food has been reset. Hopefully that will be the most enduring lesson.

[1] I'm often asked when I've broken the diet. I've broken the diet four times:

• Dan lost a bet to a group of friends and we scheduled a meal at Manresa;
• Thanksgiving;
• I was at a wedding that instead of normal, boring catering had a New Haven thin-crust pizza truck roll up and cook pizzas fresh; and,
• I went to Japan for a week and wasn't not going to eat any carbs, which would have been quite difficult anyway.