How tracking food can help you lose weight

Sometimes all it takes is one tiny switch to set off a cascade of change. And there’s no better example than starting to log your food, activity, and weight. “Tracking is what we call a ‘keystone habit,’ which means that practicing it tends to lead to other positive changes in behavior that support weight health,” says Lindsey Parnarouskis, Ph.D., manager of clinical research and behavioral science at Weight Watchers. 

Documenting what you eat, how much you move, and whether you're gaining, losing, or maintaining your weight not only builds awareness of your choices in the moment, but it provides helpful information you can use to fine-tune your lifestyle habits going forward. Bonus: It also delivers a steady stream of small rewards to help you feel motivated to stick with them. Here’s a closer look at how simply tracking your daily stats does all that and more.

There’s a vast body of evidence confirming the benefits of tracking your food, or “self-monitoring,” as scientists call it. For example, in one recent review of a decade’s worth of studies, researchers at Stanford, Duke, and the San Francisco VA Health Care System found that tracking was consistently linked with greater weight loss — especially during the first year of the journey. And a big reason for this comes down to the fact that data doesn’t lie. 

“We tend not to be very accurate at assessing our behavior patterns — for example, we may generally feel like we’re exercising ‘a lot’ or ‘a little’ or have a general sense that we’re overeating, but we don’t know by how much or what might be driving it,” says Parnarouskis. 

Recording your actual portions and movement gives you real-time factual information about exactly how much energy you’re consuming and expending. “Seeing our own data laid out in front of us helps us see patterns and make more informed decisions,” says Parnarouskis. “It can also help you give yourself credit for things you did well when you otherwise would have labeled it a ‘bad’ week, or recognize that you’d like to shift something and set a realistic goal.”

The mere act of pausing to enter your meal or snack provides an additional benefit: Snapping you out of eating on autopilot. “Tracking encourages us to slow down and become more aware of our behavior in the moment,” says Parnarouskis. “Even when we track after the fact, knowing that we’re going to record what we’re doing helps us become more conscious of what’s happening in the present moment. This can help interrupt our automatic patterns and give us more choice about what to do next.” That written record, right there in black and white, adds an extra layer of accountability — to yourself. “Even if no one else will see it, it can make us more likely to act in accordance with our goals,” says Parnarouskis.

You don’t need to aim for perfection where you track every single day, but the more you do it, the better. A 2023 study of Weight Watchers members found that tracking at least 20 days each month was enough for participants to successfully lose 10% of their body weight in six months. For comparison, tracking only two days a week (around eight days a month) was associated with a 3% weight loss. “The more people tracked, the more likely they were to reach higher weight-loss thresholds,” says Parnarouskis. This is why the Weight Watchers Core Program makes tracking as easy as possible, even letting you log some meals with a picture or scan of a barcode.

To really stick with a new habit, you need to have three elements: 

• The cue: This is something in your environment that leads you to a behavior.

• The routine: The habit or behavior itself — the thing you actually do. 

• The reward: The positive consequences of the routine that make you more likely to do it again in the future. 

These three things lead to what’s known as a habit loop, where you keep repeating the behavior until it becomes almost automatic. Many people only focus on the routine — what they want the new habit to be — and forget to think about the cue or the reward. That’s where tracking with an app like Weight Watchers helps. For cues, you may get a notification that reminds you to log your recent meal or your weight or decide that every time you sit down to eat, you first track your meal or snack. 

Then come the built-in rewards: The dopamine bump of seeing your days-long streak of logging in or encouragement from fellow members in the comments. “You also get the added reward of starting to see yourself as someone who takes consistent action toward your goals — which makes you even more likely to maintain your new habits,” says Parnarouskis.

And while at first tracking may seem like it’s taking a lot of time, you’ll be able to do it faster the more you do it. Research from the University of Vermont found that participants took 23 minutes a day to log their food at the beginning of the study and less than 15 minutes a day at the six-month mark.

Avoid common mistakes and maximize your healthy habit loop with these pro tips:

1. Try habit stacking. Pair tracking with something you already do automatically, suggests Parnarouskis, so that you’re more likely to remember to do it. The logical example here is to log your food right after you eat each meal or snack. You’ll get the added benefit of increased accuracy, since the food will be fresh in your mind.

2. Make it a photo finish. Don’t have time to track in the moment? Take a pic of your plate before you start eating and log the foods later. The image will help you remember exactly what you ate and how much.

3. Pre-track your meal. Better yet, write down what you plan to eat before you’ve even eaten it. Planning ahead will help you determine how many Points you have to spend and what you want to spend them on. Try to remember to adjust what you pre-tracked to what you actually ate to make sure it’s accurate.

4. Ditch all-or-nothing thinking.  “It’s common for people starting out to believe it’s only helpful if they track every single thing,” says Parnarouskis. This sounds good in theory, but if you miss a day or a meal (as everyone does from time to time), you can fall into the trap of thinking tracking is too hard, or not a good fit for you. “While we know that more frequent tracking is associated with more weight loss, you don’t have to record everything 100% of the time to reap the benefits,” she says. “Start small and work toward consistency, not perfection.” 

5. Embrace the humblebrag. Boost the reward you get from tracking by sharing your successes with someone supportive. Connect is a great place to do this, but it can also look like simply telling a friend or family member about your seven-day food logging streak. Go you!

6. Track it all. You might find yourself ghosting your tracking app when you’re not thrilled with the choices you’ve made. Maybe you know the cookies you had for dessert will put you over your Points budget, or you avoid tracking your exercise when it’s less than usual during a vacation. “When this happens, it can be helpful to remember that the act of tracking itself is helpful for weight loss, regardless of the content,” says Parnarouskis.

Tracking your food, activity, and weight isn’t just busy work — it’s a key habit that helps you make smarter choices and build lasting momentum. That’s why it’s a key component of the Weight Watchers Points Program. You don’t need to be perfect, but tracking more frequently is associated with more weight loss. Seeing what you’re actually eating and how much you’re really exercising gives you insight into your habits and steady reinforcement for the changes you want to make.