When to get medical advice

You lose weight without trying

If you keep losing weight without changing what you eat or how you move, have a doctor look into it. If you have other symptoms too, do this as soon as possible.^[1]

Food or numbers weigh on you

Anyone can get an eating disorder. Possible signs are sudden, significant weight loss, exercising a lot, lying about food or weight, and avoiding meals with others. If you think this may apply to you, see a doctor as soon as you can.^[2]

• Germany: helpline of the Federal Institute of Public Health, 0221 892031, Monday to Thursday 10 a.m. to 10 p.m., Friday to Sunday 10 a.m. to 6 p.m.^[3]
• United Kingdom: Beat, 0808 801 0677.^[2]

The app offers no plan in this case, because counting calories and fasting can make an eating disorder worse.

Before you start

Talk to your doctor first if any of these apply to you:

• You are pregnant or breastfeeding. You should then avoid the fasting-mimicking diet, one form of fasting.^[4]
• You have diabetes or another chronic illness.^[5]
• You take medication regularly. Also ask at the pharmacy whether meal times or fasting matter.

You want to eat very little

Diets of 800 kcal a day or less count as very low-calorie. According to a task force of the US National Institutes of Health, they belong under medical supervision. The most common serious complication is gallstones.^[6]

You have severe symptoms

With severe or sudden symptoms, do not wait for an appointment and get medical help right away.