The scale went up a pound within a week but i didn't eat any differently. why is this? thanks!

Many possibilities: There are many reasons why weight fluctuates. I have patients who report up to 5 pound weight swings in a day! Your weight is not just a reflection of body fat but also water weight as well as the food and drink you've recently consumed. Thus, your weight will change with the time of day, monthly cycle and state of hydration. Good luck!

Wouldnt stress: Weight is a complex byproduct of calories in vs. calories burned for starters. Several other factors play a role including metabolism, hormonal effects and exercise. In addition, weight can vary depending on the time of day it is measured, the season, level of hydration and even the scale used.Thus one pound is not indicative of a trend & if your diet hasnt changed check your calorie counts

Various reasons: Weight may vary slightly because of some changes in physical activities, fluid retention, fluid loss or very subtle differences in calorie intake. Weight also varies from morning to night. Of course the tendency to gain or lose a pound varies between different people.