Eat too many calories from any food, and you will gain weight. But since cucumbers are extremely low in calories, you'd have to consume several dozen of them to make a significant impact on your size. Your weight gain is more likely caused by other foods you're eating in excess, including refined grains, sugar or saturated fats. If you eat a relatively clean diet, weight gain can also come if you eat too many healthy, calorie-dense foods, including nuts and nut butter, whole-grains and dried fruit. Overnight weight gain may be natural fluctuations of the scale from water retention, digestion and inflammation.
How Weight Gain Happens
Weight gain occurs when you eat calories in excess of your daily requirements to fuel basic functions, such as breathing and pumping blood; do chores; exercise and assist digestion. Most adults need between 1,600 and 3,000 calories daily to maintain their weight, depending on age, gender, size and activity level.
Even consuming a slight surplus above these maintenance calorie levels can cause weight gain over time. For example, eat an 100 extra calories per day for a year and gain just over 10 pounds, since a pound of fat equals 3,500 calories.
Cucumbers and Short-Term Weight Gain
One cup of sliced cucumbers contains 14 calories, so you'd need to ingest more than 7 cups of them every day, in addition to all the other food you normally eat, to add 10 pounds in one year. It's highly unlikely that you could consume this much and even less likely that you could eat enough of them to add a 1/2 pound to 1 pound per week. You'd need to eat 125 to 250 cups of sliced cucumber in addition to your meals every seven days for them to make a noticeable impact on your weight in a week or two.
Since they contain large amounts of water that contribute to feelings of fullness, cucumbers are actually considered a good food to help with weight loss.
The More Likely Weight Gain Culprits
If you're eating cucumbers with dips or dressings, it might be these accessories that are causing your weight gain. Hummus, although healthy, boasts 400 calories per cup, a little less than a commercial 10-ounce container. Ranch dressing has 63 calories per tablespoon, which is a dollop about the size of your thumb. A salad including cucumbers, but topped with cheese, bacon bits, avocado, croutons and sunflower seeds, could also tip your calorie intake scales, literally.
Cucumbers are a good choice in lieu of chips for dipping and as a way to add bulk to a salad, but control the portions of the dip you use and keep your salad delicious, but under calorie control, by adding just one, or two, high-calorie toppings.
Normal Weight Fluctuations
If you went on a cucumber binge yesterday and your weight is higher today, it's unlikely the cucumbers' fault. Chances are that hormones or a salty meal is to blame. Your weight should even out after a day or two of eating and exercising normally.
If the pounds hang on for a week or more, your diet and exercise habits may need some revision. Avoid sugary treats, fancy coffees, soda and processed snacks and increase the duration of your workouts by 10 minutes, or add extra intensity. Always weigh yourself under the same conditions; the addition of clothes or a meal eaten an hour prior to weighing can affect your numbers.