If you notice your weight has gone up right after you've had a glass of water or a fiber-rich snack, don't worry. Water and fiber don't cause permanent weight gain; in fact, they're often linked to weight loss. If you're experiencing unexplained weight gain, however, check with your doctor to make sure an underlying health issue isn't causing the problem.
Water and Weight Gain
If you drink two 8-ounce cups of water, then weigh yourself, your weight will go up about 1 pound, but it isn't caused by a gain of additional fat or muscle. As soon as the water works its way through your system, the extra pound will go away.
You should also take into consideration what's typically called "water weight." Eating a lot of carbohydrates, consuming a large amount of sodium, being sedentary and not drinking enough water during the day can cause your body to retain extra water, temporarily pushing your number on the scale upward. Weight fluctuates from one day to the next or even from dawn to dusk the same day, and it can comprise 1 to 4 percent of your body weight, according to a study published in the Journal of Human Nutrition and Dietetics in 2013. For a person weighing 150 pounds, that gain is up to 6 pounds. Weigh yourself on the same weekday -- first thing in the morning after using the bathroom -- to get a better idea of whether or not you're truly gaining or losing weight.
Water's Potential Effects on Weight Loss
Drinking more water may help with weight loss, according to a study published in Obesity in 2008. Women in this study followed one of four different diets, and over the course of the 12-month study those who drank more water lost about 5 more pounds and also decreased their body fat and waist circumference, regardless of which diet they were following. The timing of your water intake may make a difference, too. Drinking water before your meals will help fill you up so it's easier to eat less during your meal.
Fiber and Weight
If you suddenly start eating a lot of high-fiber foods, such as whole grains, fruits and veggies, you may get a little constipated from the large increase in fiber. Constipation is most likely if you don't drink plenty of water along with these fiber-filled foods. Gradually increase the amount of liquid you consume as you add more fiber to your diet to help limit the risk for constipation and other potential side effects, such as bloating and gas. Once your system is used to dealing with the extra fiber, these symptoms should go away.
Like water, a higher intake of dietary fiber is often associated with weight loss, not weight gain. For example, study participants reported a loss of an extra pound for every 2 grams of fiber they consumed daily over the course of a 20-month study, reports The Journal of Nutrition in 2009. Fiber is very filling, so the more you consume, the easier it is to decrease the total number of calories you're consuming and lose weight. It doesn't take much to get more fiber in your diet. For example, a cup of blackberries has almost 8 grams of fiber, a cup of oatmeal has 4 grams, and a cup of lentils has almost 16 grams.
Recommended Water and Fiber Intakes
If you want to avoid increases in water weight and limit your risk for weight gain, be sure to get the recommended amounts of both fiber and water in your diet. Men should consume 30 to 38 grams of fiber per day, depending on age, and women need 21 to 25 grams of fiber daily. Switching to whole grains instead of refined grains can help you get more fiber in your diet, as can swapping some of the ground meat in your favorite dishes for beans and adding more fruits and vegetables to your meals.
Drink enough water so that your urine is clear or light yellow, as needs can vary based on a number of different factors, including the temperature of your environment and your activity level throughout the day. Typically, you need between eight and 12 cups of water daily, but eating a high-fiber diet could further increase your water needs.