Water retention and weight: what is normal

Everyday causes

• Salt: a salty meal makes your body hold more water to keep sodium levels balanced. Takeaways, ready meals, crisps and processed meats are common sources.
• Carbohydrates: each gram of stored carbohydrate (glycogen) holds roughly three grams of water. A high-carb day or the end of a diet break can add a kilo or more.
• Menstrual cycle: many women hold extra water in the days before a period.
• New or harder training: muscles hold extra fluid while they repair, especially after an unfamiliar or tough session.
• Heat: blood vessels widen in hot weather and fluid can pool in the legs and feet.
• Long spells of sitting or standing: flights, car journeys and long shifts can leave ankles swollen.
• Alcohol: a night out often brings salty food and poor sleep, and many people feel puffy the next day.
• Stress and poor sleep: both can influence the hormones that affect fluid balance.
• Creatine: often adds a little water to the muscles in the first few weeks, which is harmless. See creatine explained.
• Some medicines: including certain blood pressure tablets, steroids, some diabetes medicines, anti-inflammatories and hormonal treatments. Never stop a prescribed medicine without speaking to your GP.

What helps

Most everyday water retention settles on its own within a few days. A few simple habits help it along:

• Drink normally. Cutting back on water does not reduce retention and can make you feel worse. Our guide to hydration has sensible targets.
• Keep salt moderate and consistent. The UK recommendation is no more than 6 g of salt a day for adults, and big swings in salt cause big swings in water.
• Eat potassium-rich foods such as potatoes, bananas, beans, yoghurt and leafy vegetables, which help balance sodium. Our guide to electrolytes explains how they work.
• Move. Walking and calf muscle activity help pump fluid back up from the legs. On long journeys, get up regularly or do ankle circles.
• Put your feet up for a while in the evening if your ankles swell after a long day standing.
• Sleep and manage stress where you can.

Water pills and quick fixes

Water pills and detox products marketed for bloating usually work as diuretics or laxatives. They make you lose water temporarily, which comes straight back, and they can cause dehydration and upset your salt balance. Prescription diuretics are real medicines used for specific conditions under medical supervision, not for weight loss.

In the same way, sauna suits and sweat sessions before a weigh-in only shift water. They tell you nothing about fat loss, and they can leave you dehydrated and dizzy, especially if you then train.

When it is not normal

See your GP if you have swelling that:

• lasts more than a few days or keeps coming back without an obvious cause
• affects only one leg or arm
• comes with sudden weight gain of a few kilos over a few days
• leaves a dent when you press the skin for a few seconds and is getting worse
• appears around your eyes or face, particularly with foamy urine
• started after you began a new medicine

Persistent swelling can be a sign of heart, kidney, liver or circulation problems, or a side effect of a medicine, and it needs checking rather than guessing.

When to get urgent help

Call 999 or go to A&E if swelling comes with shortness of breath, chest pain, difficulty breathing (especially when lying down) or coughing up blood, or if your face, lips, tongue or throat suddenly swell.

Get an urgent GP appointment or contact NHS 111 if one leg, usually the calf, becomes swollen, painful, warm and red, particularly after surgery, a long journey or a spell of immobility. This can be a sign of a blood clot (DVT). If you are unsure how urgent something is, NHS 111 can help you decide where to go.

Keeping perspective

For most people, a few days of puffiness after a salty meal, a tough session or a long journey is nothing to worry about. Keep your habits steady, compare weekly averages rather than single mornings, and use your waist measurement and progress photos alongside the scales. Measuring progress beyond the scales shows how to set that up. If you have periods, comparing the same point in your cycle from month to month removes a lot of the noise.

Swelling around a single joint after training or an injury is a different matter from general water retention. Lycan Strength's on-site physiotherapy can assess muscle and joint problems, and members get 20% off treatment.