Overnight Weight Gain

Waking up to a gain of several pounds overnight can be incredibly discouraging, especially if you feel like the last few days have been successful. Long-term weight loss is a “two steps forward, one step back” process. A few pounds overnight is almost never actually fat gain, but instead just a result of water retention. Don’t worry — once you identify the cause, it will come off as quickly as you gained it.

Low or Falling Ketone Levels

If you experience rapid weight gain and your ketone levels are low or falling, this is most likely caused by eating beyond your macros, especially in protein and carbs. The extra sugar you get from eating too much protein and carbs will get stored as glycogen, which is bound to heavy water molecules and could be the source of such a quick change in weight.


Though it might seem backwards, exercise can lead to small amounts of rapid weight gain. This is also a product of water weight: exercise involves putting stress on your muscle fibers, causing micro-tears and inflammation, which then leads to more muscle. The body’s healing process involves retaining extra water to assist with the healing process. The inflammation weight does disappear as the muscle is built, and regular exercise will always help weight-loss over time.

Getting Back to Weight Loss

Even though it’s defeating to see those extra pounds appear overnight, water weight is nothing to worry about. If you keep eating to your macros, you will eventually lose it and continue on to burn fat.

  • Be sure you are measuring and tracking accurately. Eyeballing portions or eating out can lead to eating beyond your macros without you knowing. This includes any snacking, nibbling, or tasting while cooking. Consistency is very important for a keto diet.

  • Avoid non-keto foods as well as high-carb veggies like onions, brussel sprouts, and bell peppers. Remember that tomatoes are a fruit and contain enough sugar to inhibit or prevent ketosis.

  • Eliminate alcohol from your diet. In addition to slowing down fat burning, alcohol can add a lot of calories or carbs you might not be tracking. Drinking also intensifies cravings and makes you more susceptible to them.

  • Measure your ketone levels daily. Measuring gives you a better understanding of your progress and how your body is responding to the foods you eat. Blood ketone meters provide a high level of accuracy, giving you better insight into these responses.