No, you didn't really gain a lb overnight

Here's a common scenario that you may be able to relate to. You've been diligently pursuing your fitness goals for weeks, keeping a close eye on both your nutrition and your exercise routine. Then one morning, you step on the scale and—bam!—the number has jumped up over a pound since yesterday. You've been doing everything by the book, so what went wrong? Why does the universe hate you?

At this point, you are disheartened and frustrated. You may be tempted to give up on your goals altogether, seeing how impossible it now seems to reach them. But, hang in there! Let me explain why it's not yet time to quit.

You probably didn't gain a pound of fat.

The first thing to understand is that gaining a pound of more of body fat overnight is highly unlikely. By that, I mean that you would have to make a real effort to eat enough in one day to achieve a full pound of weight gain.

Let me put it this way: 1 lb of body fat requires you to consume 3,500 calories in addition to what you normally eat. To put that in context, here are some foods that pack on the equivalent of 3,500 calories:

• 1.5 large pepperoni pizzas (12 slices) from Domino's
• 4 pints of Haagan Dazs chocolate ice cream
• 7 large servings of McDonald's fries
• 18 Krispy Kreme Original Glazed donuts
• 24 bottles of Budweiser beer

Get the idea? Even if you enjoyed a fun night out on the town with friends, it wouldn't be enough to derail your fitness goals, unless all of you were deliberately binge eating to the point of pain.

So what is really going on here?

It's mostly water weight.

The short of it is that you gained mostly water, not fat. It is actually very normal for your body weight to fluctuate day to day, by several pounds or more. And most of this fluctuation is due to temporary changes in the amount of water that your body holds onto. One day, you could be holding onto a lot of water (and thus be a few lbs heavier on the scale), only to have it all flush out of you when you go to the bathroom the next day. Our bodies are just fickle like that.

There are many reasons your body may be holding onto more water than it normally does, but here are a few of the common culprits:

1. Salt intake: Eating more salty foods than usual can lead your body to retain more water, to ensure that your blood doesn't get too salty. You can get rid of the excess salt and water by drinking more water the next day.
2. Carbohydrate intake: Not many people realize this, but the key is in the name: carbohydrate. Basically, every molecule of carb that is stored in your body attaches itself to 4 molecules of water. So after you eat a particularly carb-rich meal, your body weight can temporarily increase due to water weight.
3. Exercise intensity: Pushing yourself harder in the gym? Your body naturally responds to intense exercise with by becoming inflamed. This inflammation can cause a temporary increase in water retention, and a higher number on the scale. Not to fear, this is a normal response to exercise as your body works on repairing and strengthening itself.
4. Stress level: Elevated stress can cause your body to overproduce a hormone called cortisol, which in turn can cause your body to hold onto water. Even if you're sticking to your diet to a T, a stressful week can reflect as a sudden spike in weight.
5. Menstrual cycle: If you're a woman, you probably already know that it's normal to see your scale weight bump up anywhere between 1-5 lbs in the days before your period. This is due to changes in the female hormones, progesterone and estrogen, during this time of the month. Don't fret, your weight will naturally drop back down a few days into your period.

A better way to track progress

Daily weight fluctuations are normal and are often indicative of body water, not body fat (which is what we're usually interested in changing). So focusing too much on day-to-day changes on the scale can be misleading and discouraging. But, you still might want a measurement of progress to tell you if what you're doing is getting you closer to your goal.

A good alternative to get a more accurate picture of your progress, is considering averages instead of individual data points. Averaging your weight across at least three measurements per week and comparing these weekly averages over time can help to smooth out the fluctuations and give you a better sense of how you are trending over time.

Your fitness journey will have lots of ups and downs, so remember to be gentle with yourself along the way. If you put in a consistent effort, a few off days aren't going to break you. As long as you stay focused and patient, and trust the process, you will move toward your goals in the long term!