I read that OOLong Tea helps with Weightloss

First let me assure you: Drinking oolong tea does help you lose weight.
Even in traditional tea drinking countries like China and Japan, it has a huge reputation and following for helping people keep slim.
It is widely accepted in China that all teas - especially green tea, oolong tea and pu-erh tea - "make one thin."
Oolong tea is not as well studied as green tea. But there is decent scientific evidence that it helps lose weight by

• Increasing metabolism
  
• Burning fat (through a process called lipolysis)
  
• 
  Blocking dietary fat absorption
  

Oolong Tea Weight Loss Study - How It Works

Oolong Tea Weight Loss Fact #2:
Fat Blocker

In Asia, oolong tea is a popular accompaniment for greasy food.
Now, scientists have proven that it is an effective fat blocker.
A study conducted by the University of Tokushima found that it can double the amount of fat being excreted.
12 young Japanese adults participated in the 17-day study, consisting of 10 days of washout and 7 days of treatment.
The scientists found that fat excretion was twice as high for those who consumed oolong tea compared to the placebo.
Oolong Tea Diet Blocks Fat Absorption

Oolong Tea Weight Loss Fact #3:
Keep Slim

After you have lost weight successfully, you face a long fight to keep fats from piling on.
What do you do? I don't really recommend consuming fat burner supplements for longer than 3 months. They might be toxic when accumulated over the long term.
This is when a suitable tea beverage comes in. They are proven natural fat burner over the long term.

In addition, their triglyceride fats were 80% lower.
Oolong Tea For Fat Loss - An Ideal Weight Watcher

Oolong Tea Weight Loss Fact #4:
Reduce Belly Fat & Cholesterols

A 2001 Japanese study found that drinking 1 litre of oolong tea a day can take 2 years off the internal organ age.
Out of the 11 participants, 9 experienced 2 centimeters reduction in their waist size and 8 experienced 2 centimeters reduction in their upper arms.
They also observed lower cholesterols levels.
Oolong Tea Anti-Obesity Benefits - How It Reduce Belly Fat and Cholesterols