Garlic can help with weight loss because it is rich in allicin which is a compound released when garlic is chopped or crushed. Allicin has many health benefits such as reduced inflammation, antioxidants and even weight reduction. High cooking temperatures can kill allicin, but allicin is found in raw garlic (if you can stomach it!).
Allicin is responsible for boosting energy levels and your metabolism which is what helps you burn calories more effectively and consequently lose weight more efficiently.