how can cinnamon increase weight loss?

You can take cinnamon supplements for weight loss before meal or add cinnamon powder to food like smoothies, yogurt or even a cup of hot tea. 
Here's how you can supercharge your cinnamon weight loss effort – add honey to it. If you like to try the honey and cinnamon drink, we recommend adding 1/2 teaspoon (tsp) of cinnamon powder and 1 tsp of honey to 8 ounces of water. Mix them together and drink half of it before going to bed. Refrigerate the balance and drink it the first thing in the morning with an empty stomach. Do not heat it up. Personally, I like mixing honey and cinnamon powder to my oatmeal during breakfast. 
Drinking this honey and cinnamon weight loss mixture daily has helped individuals to achieve good fat loss results. They were able to get rid of body fat particularly those around the stomach area and drop pounds. Be forewarned that 4 grams of this herb per day (about 1.5 tsps) is possibly the maximum amount anyone should consume as suggested by Tim. 
The second thing is that cinnamon contains the chemical compound, coumarin. At high concentration, coumarin can damage the kidney and liver. All 3 species of the herb contain coumarin but the level is significantly lower in Ceylon (true) cinnamon compare to Saigon or Chinese (cassia) species. 
Further to that, coumarin can have a "blood-thinning" effect, so for those on anti clotting medication or suffer from bleeding disorders please abstain from going on cinnamon weight loss plan unless with doctor's approval.