Stay thin when you run
When you are in the middle of the level, it is a good idea to lose the best possible weight. That will make it easier to overcome most obstacles. There is a point where it may not be possible not to gain weight, but try and make sure you balance the weight gain by taking some healthy foods as soon as possible.
Only heavy characters can break glass
At the end of the level, you have to fatten to break the glass. There's always a big chunk of fatty food and a big chunk of thinning food on the way to the chest. Grab the fatty food to break through the glass, then grab the thinning food to jump over other obstacles. Sometimes you'll make it big when you get to the end, but that doesn't seem to be the case.
Watch out for traps
The glass floor is one of the most difficult obstacles in the game, especially if there is a layer of fatty food. That's because if you get too big, you'll crack the floor and fall to your death. Try and avoid picking up fatty foods when you run into any obstacle - that's definitely a surefire way to fall down and have to start the game again.
New clothes and food are just cosmetics
You can buy new clothes with the money you earn, and new foods are unlocked as you play. All they do is change how the game looks, so don't worry too much about watching videos to speed up the process. You'll unlock everything naturally, so focus on having fun.
Too fat, can't forget it
If you are too fat, you will not be able to get past the obstacles. That's as true at the end of the level as it is in the middle. The key to success is balance – make sure you are not too heavy to reach the end. If you look too heavy, make sure you grab a healthy diet before you hit the next hurdle.