Pros and Cons of Keeping a Diet Log


As a society, we’ve become sort of obsessed with gathering data about various health-related activities, like how many calories we take in, how many hours of sleep we get, and how many steps we take. Diet tracking apps, which allow you to log your food intake throughout the day, are among the most popular category of mobile apps. Chances are good that you’ve at least tried using an app like MyFitnessPal to track what you eat, perhaps in conjunction with an activity tracker like the Fitbit.

There are a lot of potential advantages to keeping a diet log but also some possible pitfalls. Here are what I see as some of the main pros and cons of diet tracking

Advantages of keeping a diet log


Keeping a record of every single thing you eat definitely increases your awareness of your eating behavior. This is especially true if you tend to eat unconsciously or in response to external triggers.

People who commit to keeping a strict log are often amazed to realize how often they eat throughout the day. For example, you might estimate that you only eat once or twice between meals and be amazed to discover that you actually eat 6 or 7 times outside of mealtime.

Obviously, if you can’t even remember eating that Hershey’s kiss from the bowl on your coworker’s desk, you didn’t enjoy it that much.  And unconscious or mindless eating is a frequent source of excess calories.


Keeping a diet log also introduces a degree of accountability, even if it’s only to yourself.  If you’re truly committed to writing down every bite, you might find yourself thinking twice about going back for that second bowl of ice cream, simply because you don’t want it staring back at you from your log at the end of the day.

The accountability factor is even more compelling if you are sharing your diet log with a trainer or coach or even with friends or strangers. Most of the diet tracking apps take full advantage of this by building in a lot of social features, where you can choose to share your log with others who are using the app or on your social media channels. The desire to keep up appearances seems to be extremely motivating for a lot of people.


Most diet trackers will also provide a certain amount of analysis about what you eat…some are quite detailed.  You can learn a lot of useful information this way, such as how much protein or calcium or sugar or sodium you typically consume. You can use this information to make adjustments if necessary. This can also be extremely useful information to share if you are working with a nutrition professional.

Although you can use a diet tracker to analyze and improve your diet choices, it really shouldn’t be necessary to do this forever. Although we usually express nutrition requirements on a per day basis, as in “1000 mg of calcium per day,” it’s not necessary to get exactly 1,000 mg of calcium every day. It’s fine if you get 800 today and 1100 tomorrow. The same is true of just about any nutrient you can think of. Although jenga-ing together a “perfect” day can be a fun little game, that degree of precision is really not necessary for good nutrition.

After a while, you should get the hang of which kinds of foods and meals add up to a complete and balanced diet, what sort of portion sizes are appropriate for your calorie needs, which foods you are better off avoiding all together,  and even how often you can afford to splurge on a treat.


And finally, keeping a detailed diet log can be a good way to figure out whether a food (or foods) could be responsible for symptoms such as headaches or sinus infections or digestive issues. The trick here is to keep track not only of what you eat but also keep a log of any symptoms you are experiencing. Sometimes, you (or your nutrition professional) can detect a pattern that might not be immediately obvious. It can also be used to rule out suspected causes.

You might also find behavioral insights in your diet log, such as the fact that having a couple of drinks with dinner increases how much food you consume over the course of the evening. Or that you tend to eat more at lunch after eating cereal for breakfast than you do if you eat eggs. You might discover that eating very little on one day leads you to overcompensate the next, resulting in a net increase in calories.  As they say, knowledge is power.

Potential Pitfalls of Diet Tracking

I have kept food diaries at various times, although never for more than a week or so. I have asked clients to keep them so that I could assess their diets and suggest changes, but only as a short term exercise in information gathering. Because I think there’s a potential downside to completely outsourcing our ability to make good choices about what and how much to eat.

Listening to Internal Signals

For one thing, I think it’s enormously valuable to develop an internal ability to know whether you are hungry and when you’ve had enough to eat. If the only way you know to stop eating is when your calorie counter reaches your daily limit, it’s time to tune in and start noticing (and trusting) what “enough” actually looks like on your plate and feels like in your stomach.

This assumes. of course. that you’re not trying to limit your calories to an excessively low number in order to lose weight quickly or to maintain a weight that’s too low. In that case, your natural appetite signals aren’t going to help too much because you’ll always be hungry.

It’s also possible that your hunger signals are somewhat untrustworthy because you are confusing other signals with hunger.

It’s also possible that your hunger signals are somewhat untrustworthy because you are confusing other signals with hunger. In that case, keeping a diet log might help. What might be even more helpful is learning to distinguish actual physical hunger from triggers that are not really about physical hunger. When we have a better understanding of what these triggers are,  we can address them more constructively.

Don’t Outsource Your Motivation

And finally, while a diet tracker can provide some motivation to stick to your plan, I think it’s a mistake to completely outsource or externalize our motivation.

It may be rewarding on some level when your diet tracker give you a green checkmark or whatever it gives you when you hit your targets. But obviously the payoff to eating well is not getting a gold star on our devices but in the physical and mental well-being that we get, both from the nourishment but also from knowing that we’re taking good care of ourselves and that our choices line up with our goals and values.

Diet trackers have their place. But if keeping a diet log is the only thing that keeps you from overeating, you might benefit from thinking about your deeper motivation. Maintaining a healthy weight might help you avoid knee surgery, or help you sleep better and feel better as a result, or reduce your risk of developing Type 2 diabetes, which in turn increases your chances of living longer. These are payoffs far more rewarding than the approval of your diet tracking app.