Here are a few ways to avoid the weight gain during marriage season:
1. Increase liquid intake. Have a lot of water/fluids.
2. Once a week, do a detox. See
http://www.lifemojo.com/lifestyle/detox-diets-421233. Have your dinner light.
4. Do a portion control while having sweets.
5. Have missi roti or besan roti instead of naan / kulcha / paratha.
6. Have soup and salad before starting your meal. Fill your plate with salads, so you would have less of other stuff.
Enjoy the marriage season, but do not neglect your health.