How can she do it?

Just had a bried chat with my chief tenant, she doesn't quite look that old, i mean compare to her actual age. She's look very the same as me, eventhough she's older than my sister. My elder sis actually looked older than her. (I'm so bad!) And then i got another shock, she told me last time her weight is more than 70! Gosh! She's much slimmer than me now! How can she do it? And she lost all the extra pounds in 2 months time, without going to any saloon or took diet food. She just told me, everything that goes into your mouth, will eventually shows on your body, if you don't control. I'm so impressed, she's very discliplined. Can reduce her weight from 70 sth to now 50 ( i think), must be controling the diet very much. I think i need to be like that. Now i have another role model other than ah boon! Really need to disclipline myself to lose weight. I know i'm in my ideal weight, but i wanna look slimmer! seems like my whole life is only losing weight, but i really do enjoy this leh. I love my life!