• Only eat until you are 80% full. This is called Hara Hachi Bu in Japanese and goes back to Confucian teachings.
• Avoid eating 3 hours before bedtime. If you are hungry, eat a small light snack or meal that's easy to digest.
• Drink a glass of cold water when you first wake up. This kick-starts the metabolism in the morning. Optionally add some lemon slices for their detoxing effect.
• Eat smaller meals more frequently.
• Swap larger plates and bowls for smaller ones.
• Stop drinking fizzy sugary drinks. Drink water and green tea instead. If that's tough, then slowly wean yourself off them, switch to fruit juice or cordial and slowly transition to water.
• Try to wean yourself off sugary snacks. Swap them for fruit.
• Drink a glass of water 30 minutes before each meal. This helps to fill up your stomach and you will eat less.
• Don't order sides with meals in restaurants. If there is an option to order vegetables/salad or chips, choose the salad.
• Bring more colour into your diet. Eat a variety of coloured fruits and vegetables, and less white foods (e.g. chips, potatoes, etc.)
• Drink more green tea.
• Eat more whole foods and less processed foods.
• Have a 'treat day' once a week, when you can eat your favourite treat foods. This will help you to be more disciplined for the rest of the week.
• It takes 21 days to start a habit. Following the tips should become easier over time.
• True, this list of tips doesn't really address exercise. Look at this blog post on why you should exercise.

From here