Why poor sleep makes you gain weight
The connection between sleep and weight is brutal. Sleeping less than 6 hours increases ghrelin (hunger hormone) by 28% and reduces leptin (satiety hormone) by 18%. Result: you eat 300-500 extra calories the next day without noticing. A University of Chicago study showed that sleep-restricted participants lost 55% less body fat than those who slept well, even on the same diet. Your body literally resists losing weight when you do not sleep enough.
The 90-minute window before bed
The last 90 minutes before bed determine your sleep quality more than any supplement.
- Minute 90: last screen. Put your phone on night mode
- Minute 60: light dinner if you haven't eaten (under 300 kcal)
- Minute 45: warm shower (the temperature drop induces sleep)
- Minute 30: dim all house lights to minimum
- Minute 15: paper book, meditation or 4-7-8 breathing
- Minute 5: room at 18-20 degrees Celsius, total darkness
- Minute 0: same bedtime every day (including weekends)
Foods that improve sleep
What you eat for dinner directly affects how you sleep. Tryptophan (melatonin precursor) is found in turkey, banana, kiwi, tart cherries and walnuts. A 2023 study in Nutrients showed that eating 2 kiwis one hour before bed reduced time to fall asleep by 35%. Avoid caffeine after 2pm (its half-life is 6 hours). With Renzy you can track your dinner and ensure it includes sleep-promoting foods.
Renzy calculates all of this for you
Scan your food with a photo. Calories, macros and micronutrients in 3 seconds.
Action plan: your routine this week
Do not try all 10 habits at once. Start with these 3 this week and add one each week.
- Week 1: same bedtime every day + no screens 30 min before
- Week 2: add warm shower 45 min before bed
- Week 3: include 2 kiwis or a handful of walnuts at dinner
- Week 4: try 4-7-8 breathing (inhale 4s, hold 7s, exhale 8s)
Renzy calculates all of this for you
Scan your food with a photo. Calories, macros and micronutrients in 3 seconds.
