Kapalbhati pranayama is the best recommended breathing exercise to lose weight and blood sugar. Kapalbhati pranayama,strengthens the abdominal muscles , burns abdominal fat.

Surya Namaskar works on the whole body especially on the big muscle group & It helps to shred the weight.

http://www.artofliving.org/in-en/yoga/health-and-wellness/yoga-weight-loss