To be happy, guys need a chiselled chin, washboard gut and boy-band pecs.
The way to be happy is to learn to appreciate our bodies and to feel comfortable with who we are.
It's not fair expecting your body to match up to super fit adults while it's still growing. During teenage years, it's normal to grow out a bit then up a bit for a while.
Even when fully grown, very few of us end up shaped like body builders. It takes a huge amount of time, careful dieting and hours of daily effort to keep a body like that.
Out in the real world, 'normal' means a lot less beef and quite a bit more of the wobbly stuff.
In fact, we need some body fat to stay healthy. It helps protect our organs and helps the body fight off infections. The body also needs fat reserves to use in case we get sick and can't eat right for a while.
People who are too thin are much more likely to come down with colds and other common bugs and take longer to recover.
Carrying too much weight around our middles is bad for health in the long term but being too thin could affect your health right now.
Whatever age we are, it's important to know we're a healthy weight.
How? Easy - weigh yourself, measure your height and put these details together with your age into the NHS Choices special Healthy Weight Calculator (external site)
NOTE: Don't use healthy weight or 'BMI' calculators designed for adults - they don't work properly for young people and give misleading results. The calculator linked above works for everybody, no matter how old.
Ignore the bathroom mirror. For starters, who's going to see you under the glare of the bathroom light?
How we look to others has much more to do with how we carry ourselves, how we move and how we dress.
If you stand straight, shoulders back, make eye contact and smile, a funny thing happens - you actually start to feel more confident. Give it a try next time you feel a bit unsure of yourself.
Meanwhile, people who are relaxed with themselves always appear more attractive.
Learn to be happy with yourself the way you are and the self-esteem and confidence it gives you will show.
Read more about building confidence.
Dieting, unless your doctor tells you to, is a bad idea for young people. Your body will still be building itself for years to come and needs properly fed.
If you do want to tone up a bit:
- try getting more physical activity
- keep regular mealtimes and eat well
- try not to snack between meals.
Don't be fooled into thinking the perfect body will get you love or respect.
Pick up any celeb mag or browse the gossip sites (or any tabloid) and see all the 'gorgeous' people that get caught in relationship 'shockers'.