In Part I of this article, I told you about Signor Caruso, a master Italian tailor who makes some of the finest bespoke suits in all of Italy.

In making these suits, these one-of-a-kind, elegant masterpieces, Signor Caruso begins with nothing more than a simple, one-size-fits-all template. Then, with repeated measurement and alteration, Signor Caruso crafts a one-size-fits-yousuit. The Caruso process ain't cheap. You'd end up paying upwards of $4000 per suit. But in the end, the product is astounding.

Of course, I told you the story to illustrate how tailoring suits and tailoring nutrition programs is a similar process. Just as there's no magic test to determine exactly how to cut a suit to fit you perfectly every time, there's no way to come up with a nutritional perfect fit every time either. Both making a stunning suit and building a stunning body are iterative processes.

The Wrong Approach

Most trainees never reach their goals because they're waiting for the magic bullet, the one tip or trick that will finally get them the body they've been looking for.

People want to make simple, tiny, easy additions or subtractions to their current "plans," knowing full well that negligible modifications will probably yield negligible results. Adding a "superfood," magic soup, supplement, or drug won't compensate for gross misunderstanding and misapplication of key principles. Subtracting a single food or removing all carbs from your diet won't remove the real stumbling block.

Often people just want to be validated for what they're currently doing. They want to read an article on nutrition or training and say, "Well, I do some of that, so I'm probably okay," despite the fact that doing only "some of that" has left them far short of the body they could have.

Well, I'm not here to validate you. I'm not going to sugarcoat this, or dumb it down, or tell you what you want to hear. I'm here to tell you the truth, to the extent that I've ascertained it. Here's that truth:

1. If you want a drastically better body than the one you have now, you need to make a wholesale change to your nutrition plan.

2. The magnitude of that change will seem daunting and possibly intimidating. You'll question whether all this is truly necessary, and you'll be tempted to make do with less – much less.

3. The process will require a significant dose of that forgotten ingredient: discipline. Discipline is a by-product of purpose and desire, so you'll need those too. You'll need to remind yourself why you're eating this way (how lean and muscular you'll eventually be, for instance) and how much you want to reach your goals (or how it'll feel to fail yet again).

But there's more:

1. The system works. If you do it in its entirety, you'll reach your goals.

2. Though perhaps overwhelming at first, with practice it'll quickly become simple and effortless.

So what is this system, this right method? Well, in Part I, you designed a starter plan on which to build, just like the tailor builds a pattern or template for his custom suits. Now it's time to learn the art of fitting – bringing that starter plan ever closer to the perfect plan for you.

You've Got To Measure Something

I get hundred of emails each week from people asking me very specific nutrition questions. Just yesterday someone asked me if he should cut 100 grams of carbs from his diet in order to lose more fat. To be honest, unless it's blatantly obvious that the person is advanced enough to make use of this information, I don't answer. Instead, I just direct him to comprehensive articles and resources so that he can learn to answer himself.

Why? Because even if I answered in detail, he'd have no way to make use of my advice. Most people have no way of quantifying what they're doing nutritionally, and no way of making a minute change and holding that variable constant.

Unless you can tell me exactly how many grams of carbs you've been getting every day for the last month or so, and unless you have a way of controlling how many grams of carbs you'll eat for the next month – all to a reasonably high degree of accuracy – then answering such a question is a waste of time for me, and asking it is a waste of time for you.

Bottom line: Many people have no idea what they're eating. They may try to eat more protein, or have certain meals that they eat regularly, and they may even have a vague idea of how many calories they consume on a good day. If you're getting the results you want, this isn't a problem. If you aren't, however, it is. Vague ideas are of no use in the process of optimization. You need to manipulate your nutrition plan and all the variables contained in it – and you can't manipulate something you've never measured!

In The Beginning, Keep A Food Log

So the first step is to know and quantify what you're eating. Commonly, this is done by keeping a food log.

A food log is analytical; that is, it's a tool used to analyze what you've done after you've done it. It has its place, and that's prior to beginning a solid nutritional program. I have my clients do a three-day diet record in which they choose three typical days representative of their general eating habits (one work day, one training day, and one weekend day, for example) and on those days record everything they eat. I have them do this as soon as they sign up with me, for two reasons.

One, I want to see how bad their nutrition is. Two, I want them to see how bad their nutrition is. Even if they don't record their diets accurately, they'll have to make a conscious choice to fudge or omit – which is an admission to themselves (though not to me) that their nutrition is poor.

Of course, some are simply lazy and forget to record their diets, while still others are so deep in denial that they'll lie outright and feel nothing doing so. For both types, sticking to a good nutrition program will be either extremely difficult or impossible – and dealing with these types is beyond the scope of this article. For most people, diet records and food logs are excellent motivational tools and will help them commit to the new diet and the changes it necessitates.

So before you begin to manipulate your diet in earnest, do a diet record. Record everything you eat for three days, and eat as you normally would. If for some reason on one of the recording days you have to eat abnormally, scrap that day. Record again until you have three days of food records that represent your typical diet. Compare these records to the "7 Habits" outlined in Part I and see how well you're really doing.

Beyond Food Logs

While food logs do allow you to know what you're eating, they don't directly help you to manipulate your diet to accommodate change. As food logs only analyze what we've eaten, they're not helpful in dietary manipulation.

Would you enter the gym without a plan and just write down what lifts you felt like doing that day, complete with your sets, reps, and loads? And then, the next day, enter the gym in a similar manner, continuing to record useless, system-less information? Probably not.

That's why I don't recommend food logs as a way to monitor your intake. What are you going to do with that information once you've got it? Just vow to do better next time? You don't need to measure your food intake – you need to control it.

In scientific terms, your nutritional intake is the main independent variable in your body comp experiment. You don't measure independent variables, you control them, and measure results instead.

So rather than recording what you did, you should be planning what to do – and sticking to it. You don't need to analyze what you've done; you need to synthesize what to do. After that three day diet record, you no longer need a food log. You need a meal plan.

Scientifically speaking, to make progress you've got to fix your independent variables (what you eat) and measure your dependent variables (weight, lean body mass, fat mass – in other words, your body composition).

When it comes to nutrition, fix this variable by making a plan and making sure you do it. Then measure your dependent variables: your body comp results.

Eat The Same Things Every Day?

As I've recommended "fixing" your nutritional intake above, I know many of you will get confused and think I'm suggesting that you have to eat the same things every single day. I'm not.

Remember, in Part I, I recommended coming up with a variety of meals built around the 7 Habits. You can build 30 meals with similar calorie and macronutrient profiles. You can build 50. Heck, in my Precision Nutrition materials, I've built over 125! Just be sure that you've got as many meals as you need to pick from to be comfortable with your variety.

However, keep this one thing in mind before you get carried away. Most of the people with the absolute best physiques tend to eat very similar things day in and day out. So don't lose sight of this fact in your quest for unlimited variety and a great body too.

Nutritional Planning

You know now that you have to plan in advance and that you have to hold that plan constant. But how? And why?

As I said in Part I, optimizing nutrition requires a mix of informed trial and error and the scientific method. Let me explain what I mean by that. Informed trial and error means:

1. Your trials should be informed.

You need to gather the best information you can about nutrition and use it to make your nutritional choices. That's why you're here at T-Nation, that's why you're reading this article, that's why in Part I we built a plan based on the 7 Habits – to replace random manipulation with informed choices based on the best nutritional knowledge we have available to us.

The nutritional plan you start with, and every subsequent change you make to that plan, must be based on the best possible nutritional info you can get a hold of.

2. You should be performing trials.

You must not only implement what you learn about nutrition into your daily life, but implement it such that you can judge whether or not it's working for you. Don't just try things – try them and evaluate the results! This requires that your trials be performed in a certain way, and I'll describe that way in detail in the remainder of this article.

3. You should be prepared to err, and that you should have a plan to deal with errors when they're made.

You must anticipate that not all of the nutritional changes and manipulations you make will work for you – even some of the ones that work for your friends, even some that work for my clients, even some that worked for your grandparents back when they lived in the old country.

The whole point of this exercise is to determine what works for you, so be prepared to find that you may be different from those around you. You may add 400 calories to your daily diet and see no increase in lean body mass in two weeks; I may do it and put on two pounds over that same period. What do you plan to do at that point? Shake your fist at the heavens and abandon the plan? Or have another change waiting to be made just in case?

And what is this talk of the "scientific method?" Well, it's just a fancy way of saying that you need to control your diet and measure the results that the diet brings you. You understand the principle of informed trial and error, but how exactly should your trials be performed? And how can you differentiate between success and error?

The Scientific Method

That's where the scientific method comes in. Here's what it is, and how it applies to nutrition:

1. Observe the phenomena: Gather all the information about nutrition you can. Think about your ultimate goals, in terms of body composition, health, and performance. Do you want to get leaner or more muscular? Ameliorate digestive problems? Still be able to run the floor in the fourth quarter of a basketball game?

2. Form a hypothesis: Build a diet plan that will get the results you want and bring you closer to your goals. If you don't feel confident that you can do this, have someone in-the-know build the plan for you.

3. Predict outcomes on the basis of that hypothesis: Set a goal for the results of your nutrition plan. I usually work in two week blocks, so if I wanted to lose fat I might set a goal of losing two pounds of fat in two weeks.

4. Test the prediction using a controlled experiment: With a nutrition plan in hand, follow it with at least 90% accuracy for the predetermined period of time. That means controlling all the nutrition variables – you must eat exactly as you had planned.

5. Record results and compare to hypothesis: Measure the results of the past two weeks of planned eating (i.e., the controlled experiment). Using the fat loss example, after two weeks of eating according to my plan, I'd weigh myself and do a body fat measurement with skinfold calipers. If my measurement showed that I lost two or more pounds of body fat, I'd consider my hypothesis validated – eating according to my plan allowed me to lose the body fat I wanted to lose. If I wanted to lose more body fat, I'd continue with the plan until it no longer worked.

6. If results don't match the hypothesis, modify or elaborate on your hypothesis: If on the other hand I lost only one pound of body fat, lost no body fat at all, or God forbid, actually gained body fat, then I need a better hypothesis and/or a better experiment. Here are the possibilities:

a) Hypothesis was insufficient – Often the plan you came up with will be too low or too high in calories, protein, carbs, fat, etc. to get the results you wanted. You'll need to use your best, most informed guess to make a change; the general principles of your plan, however, will remain intact.

b) Hypothesis is false – The nutritional plan you came up with didn't work because it was just plain wrong, either for you or in general. If you started with a good plan based on good information and proven results with others, you should assume that this isn't the case until you have no other choice.

That is, don't abandon a good plan entirely unless you're pretty sure that it's useless for you; more often than not you just need to modify it. If you started with a plan you had little confidence in and was completely unproven, then you can consider scrapping it entirely.

c) Hypothesis was true, but experiment was faulty – Your ability to come up with a great nutritional plan is one thing; your ability to execute that plan by adhering to it consistently is quite another. If you didn't get results, but only ate 60% of your meals according to plan, you'd better work on your adherence before you change the plan itself. There's no sense in changing a plan you won't bother to execute anyway.

7. Repeat steps 2 to 6 until your experiments yield the expected results: You must continue to adjust your plan on the basis of the results you're getting from it. You make changes, try them out (holding your diet constant for two week blocks), measure the results, and amend the plan as necessary.

Practical Application?

These aren't just abstract principles I want you to understand. They drive at a very specific method you need to use if you want to tailor your nutrition to your own individual needs.

In nutritional practice, using the principle of informed trial and error and the scientific method means doing things a little differently than most. Instead of having my clients eat randomly, or telling them simply to "eat better," or giving them vague nutritional principles to act on (then figuring out whether they did or not by doing a post-mortem on their food log), I have clients follow very specific plans.

On the basis of questionnaires, tests, medical history, etc., along with my own nutritional expertise and my previous experience with clients, I come up with a hypothetical plan that I think will get the client the results that he or she wants. I'll choose the foods, the caloric content, the macronutrient ratios, the nutrient timing, everything.

Two Weeks at a Time

These plans cover two-week periods. Why two weeks? Well, it's just a number I've found to work best. It's difficult to plan for longer periods (say, one month), and such plans become either unwieldy or oversimplified. Shorter periods (say, one week) require you to plan more often and aren't quite long enough to give any changes you make a fair evaluation. Two weeks, I've found, is just right.

To prepare for those two weeks, the client and I come up with the exact meals, grocery lists, and food preparation instructions they'll need in order to execute my hypothetical plan. I make sure that the plan conforms exactly to the nutritional variables I've set. It'll have the exact caloric content, macronutrient ratios, micronutrient content, etc. As long as the plan is followed consistently, I can perform precisely the type of controlled experiment necessary to determine whether my hypothesis was correct.

In building the plan, we take into consideration their goals, their current status relative to those goals, their logistical obstacles (work or school commitments, travel, appointments, etc.) and anything else that the client or I think is relevant. All the potential problems are worked out in advance. Upon receipt of the program, all the client has to do is eat at least 90% of the meals we agreed he'd eat. There's no need for food logs – all I want to know is whether the plan was followed or not, which requires nothing more than a few checkmarks on a page. Day 1, Meal 1 . . . check. That's it.

Most people try to measure the variables; they count calories, grams of carbs, etc. – all of which is largely a waste of time. Rather, you should set the variables in advances (meal plan) hold the variables constant (execution), and instead measure the results!

The First Measurement Standard

It never ceases to amaze me how few people regularly measure the results of the choices they make. Optimization requires constant monitoring. Nutritionally, if you hope to get great results and keep them coming, you must continually measure the outcome of your efforts.

So what exactly should you measure? Well, it depends on your goal. For each type of goal, there are specific metrics you can choose to look at. I consider there to be three categories of nutrition goals: performance goals, health goals, and body composition goals.

However, before measuring results, it's important to measure adherence. Make no mistake, eating six or seven well-designed and well-planned meals a day for three weeks with 90% adherence is a serious, discipline-requiring endeavor. It's oh-so-easy to fool yourself into thinking you're doing a great job while demonstrating only 65% adherence.

So, step one, before measuring anything else, is measuring adherence. Below is an example adherence chart from a client of mine. Here's how it works:

1) Each time the client eats a meal designated for that time slot, he gets to put an "x" in the box.

2) Each time the client misses a meal, he puts a 0 in the box.

3) Each time the client eats a non-compliant meal, he puts a * in the box.

Week 1 Adherence	Meal 1	Meal 2	Meal 3	Meal 4	Meal 5	Meal 6	(Workout Drink)
Day 1 Training Day	X	X	X	X	*	X	X
Day 2 Non-Training Day	X	0	X	0	X	X	N/A
Day 3 Training Day	X	X	X	X	X	X	X
Day 4 Non-Training Day	X	X	X	0	X	X	N/A
Day 5 Training Day	X	X	X	X	X	X	X
Day 6 Training Day	X	X	X	0	X	*	X
Day 7 Non-Training Day	*	X	X	X	X	X	N/A

To evaluate this client's success, simply tally up the total meals scheduled for the week (46) and subtract the boxes that are either blank or contain a star (7). As this client missed four meals and "cheated" at three meals, he's achieved about 85% (39/46) adherence.

That's not bad. It's better than most folks would do. But it ain't good enough. We're looking for 90% adherence from our clients.

So, try this exercise out yourself. Print off two weeks of adherence sheets and monitor how well you're adhering to your plan. If, at the end of two weeks, you don't find at least 90% of those boxes with an x in them, there's absolutely no point in measuring anything else.

If you can't control the independent variable of this experiment – the meal plan and the food you're eating – why would you measure the results like body comp, body weight, etc.? The experiment is blown. At that point, you're not optimizing. You're praying.

Think I'm joking? Well let's say you try out a new nutritional plan and only adhere to it 75% of the time. And let's say you gained body fat after the first month. What do you do now?

Was it the plan itself that did you in? Was it your missed meals? You have no idea. Well, surely you'll have to try a new nutritional plan, right? Maybe you need to eat a low carb diet instead? At least you have to cut calories, right?

Well, are you going to do that either? How many calories did you eat this week? How many carbs? How many will you eat next week? You don't know because you're not adhering to the plan – to any plan. Your variable isn't controlled, so you have no way of isolating the problem.

You didn't control last week, and unless you get your house in order, you'll be spinning the wheel of fortune again next week too. If you haven't mastered the basic skill of following a plan, that is your problem!

If that's the problem, forget changing your nutrition plan. You either need to suck it up and learn some discipline, learn some food preparation strategies, or attack the fundamental belief system that's keeping you from even following a basic plan for a mere two weeks. Or give up, I guess, because there are no other alternatives.

The Next Metrics

As mentioned above, there are three categories of nutrition goals:

1. Performance Goals

Mainly relevant to athletes, these might include faster 40 yard dash times, increased powerlifting totals, faster time trials for cyclists, etc. Generally, nutrition for human performance has three parts: pre-event nutrition, post-event recovery nutrition, and long-term general preparation nutrition.

Metrics for performance goals are determined by the event itself. For individual sports, ultimately the success of the program as a whole is judged by the performance in the event: for sprinters and cyclists, their times; for powerlifters, their totals; and so on.

However, often it's difficult or impossible to separate the causes for both failure and success. For instance, if a powerlifter misses a lift or a sprinter performs poorly, do you blame the nutrition program, the training program, or something else entirely? It's often hard to say.

The problem is compounded in team sports where the player may perform well without any objective impact on team performance. For instance, a hockey player may be in great shape and following a great nutrition program, but be on a poorly performing team or be unlucky not to score more goals. Do you have him abandon the chicken salads for Big Macs?

Performance nutrition, therefore, is often geared toward:

1) Supporting recovery from the type of training the athlete will need to do to achieve success.

2) Getting the athlete the body composition that correlates most highly with success in his sport.

In other words, while ideally you want to see a direct improvement in performance from your improved nutrition (and you should certainly measure that performance), you may have to settle on improved body composition. Now that doesn't mean that you should train or eat like a bodybuilder; rather, you should train and eat first until you have the same body composition as the best athletes in your sport, then train and eat until you perform like they do.

In short, if you're trying to increase performance, measure both the performance itself (times, scores, etc.) and your body composition (see below).

2. Health Goals

While everyone touts general health, few have it as an explicit goal, even fewer follow programs that'll improve it, and fewer still measure their progress toward it. This is a huge mistake.

Part of the problem is that health is both difficult to subjectively assess, even more difficult to quantify objectively, and almost impossible to sell as an important goal to those who are in a position to learn to maintain it for life, namely the young.

Try telling an 18 year old kid that he should worry about heart disease. If you're lucky you'll get a blank stare in return. Tell him that with good nutrition he could put on 20 pounds of lean body mass and get down to 7% body fat, however, and he'll have dreams of all the ladies he'll be able to score dancing through his head. Hey, whatever works, but at some point in everyone's life, health becomes a critical issue – and the time to build the required nutritional habits for good health is early on.

But there are both plenty of reasons to measure the impact of nutrition on your health and plenty of ways to do it. For example, you could measure any or all of the following:

• Skin condition: Good nutrition can often have a marked impact on your skin. Is your skin dry and scaly? Acne or blemish ridden? You could record this and track it over time.

• Gastrointestinal health and quality of bowel movement: We often have clients come to us to help us work through GI issues, and though the process is often long and involved, for some people it's absolutely necessary. Measurements can range from simple recording of maldigestion issues to motility timing to, that's right, bowel movement measurement.

My friend Paul Chek recently shared with me his standard: according to Paul, one should be moving 12 inches of feces twice per day. So you might want to carry a ruler with you on the road. And if you're like me and your bowl movements curve into a perfect circle, you might need this handy formula: Circumference = Pi * Diameter.

• Blood values: Another way to track general health is to have regular blood work done, tracking the values over time. Your doctor can help you to choose the right metrics, but things to consider are:

Cholesterol (HDL, LDL, and HDL:LDL ratio)
Triglycerides
Hormonal tests: Testosterone, cortisol
Liver enzymes
Fasted glucose and insulin
Oral glucose tolerance test

3. Body Composition Goals

This is the big one for most people. You either want to lose fat or gain muscle, or both. Or more to the point, you want to look better naked. So what should you measure? There are a number of possibilities:

• Body weight: This should be obvious. Every two weeks, step on a scale and write your body weight down. There are a few things to note, however.

One, body weight scales tell you just that – your body weight. They give you no information as to your initial body composition (i.e., how much of that weight is lean body mass, how much is fat mass, and what your body fat percentage is), and they're no help in determining how much of the weight you gain or lose is fat mass or muscle mass.

Suffice it to say, those are important things to know, particularly when fine-tuning an already advanced nutrition plan.

Furthermore, not all scales are created equal. Most bathroom scales available on the market today are of decent quality and will probably do; your mom's pink scale from her Weight Watchers days in the 70's should probably be replaced. Better yet, use a calibrated beam scale, the type found in good gyms and in your doctor's office.

Weigh yourself at the same time and on the same day if possible, just to be consistent – but don't be too anal about this.

• Body Fat Percentage: Measuring body weight is the first part of determining body composition; measuring body fat is the second part. Once body fat percentage is determined, you can find out your fat mass and lean body mass using a few simple equations. I won't go into the various techniques, but I'll outline the three ways in which this is normally done.

1) Skinfold calipers: Measures the thickness of skinfolds at various locations. I use this method with clients all the time, not because it's the most accurate at measuring body fat percentage, but because it allows me to measure subcutaneous fat (fat below the skin) and track the fat distribution at the various specific locations.

Most people plug the thickness measurements, usually in millimeters, into equations to find body fat. Often I'll just track the thickness itself. I'm not always interested in body fat percentage – often I just want to know that I'm losing body fat over my abs, and even a one-site skinfold measurement can tell me that, and quantify the change.

2) Bioelectrical Impedance: Measures the speed of a small current as it goes through the body, and uses the differences in electrical resistance of various tissue types to determine body fat percentage.

While this method is very popular, it's not very useful. Depending on your hydration levels, you can get very different results even when your body composition hasn't actually changed. Even with controlled hydration, these devices aren't all that accurate.

3) Underwater Weighing or BodPod: Measures body fat by placing the subject in either a water tank or an air-pressure controlled chamber and uses displacement formulas to determine body fat percentage.

These methods are considered accurate enough to be used in research studies (we used a BodPod at the University of Western Ontario Human Performance Lab), but they're not without their drawbacks. They're expensive to use and difficult to find, so unless you have easy access to one, you should probably use another method.

• Girth: Using a tape measure to take girth measurements of your arms, chest, waist, etc. can be a great way to track progress – though again, it gives you no direct information about body composition change.

A two inch increase in the circumference of your upper legs could be equally a result of muscle gain or fat gain, or some combination of the two. If you want to get an idea of how much of it is fat, take a skinfold measurement at the same site. These measurements can be very helpful and informative.

You could do a comprehensive girth measurement every two weeks, or even select a single trouble area (waist, for instance) and monitor that alone. I have all my clients track girth measurements regularly, although not always every two weeks.

• Appearance: It stands to reason that if you're training to look better, or if you're a bodybuilder or fitness competitor, your perceived physical appearance itself is a valid "measurement" or indicator of progress. Subjectivity, however, is often a major problem here: people look at themselves in the mirror and are either too critical or not critical enough – or worse, they're one way today and the other way tomorrow.

Consistent and honest appraisal is difficult for some, and unbearable for others. Some people are better off working with the previous three objective measurements (body weight, body fat percentage, and girth). Others benefit from having a friend do the assessment, or having digital photos taken (although lens type, subject-to-camera distance, and lighting conditions can affect one's appearance in photos, so consistency is an issue here as well).

It's worth noting that many advanced trainees rely on perceived appearance alone to gauge progress. I'm one of them. After years of training and nutrition experience, including a few years of serious competitive bodybuilding, I can determine my body weight and body fat percentage to a relatively high degree of accuracy just by looking in the mirror (it might also be because I've had more skinfold and BodPod tests than I care to remember). Either way, you might find that this is all you need to make informed changes to your nutrition.

If all you do is weigh yourself on a bathroom scale and look at yourself in the mirror, then at least do so with a purpose. Weigh yourself on the same scale at the same time every two weeks, and when looking in the mirror, try to notice subtle changes in your physique. For the first few months, you should write it all down.

If you can commit to recording more, do so. With just a few bucks, a set of Accumeasure calibers, and this great article on body composition, you can do more. If you've got a digital camera, use that too. But unless you're a hot chick, sending me photos of you in a skimpy bathing suit will force me to alert the proper authorities.

Summary

Whatever your goals are, be they performance, health, or body composition related, select your initial nutrition plan, make sure to keep an adherence chart, select your own relevant metrics, and start tracking your progress right away.

Over time, your nutrition program should yield tangible, objective results that show up in these measurements. If it doesn't, you need to change it, according to the ideas laid out in Part III.