Age is just a number.

But when it comes to shedding pounds, that number is part of the equation. You've probably noticed that the pounds come on easier — and come off harder — as the years creep up. That's because things are changing: your hormones, your level of activity and the way your body stores fat.

Although you may still feel like you're in your 30s, the undeniable fact is that there are physiological forces at work behind the scenes, especially when it comes to losing weight.

That's not to say you need to wave the white flag of surrender. Instead, consider these small and achievable tweaks to lose weight after 50:

1. Take up weights. You need not join a gym full of buff muscleheads to reap the benefits of weight training. But it would be wise to pick up some weights, since you also lose muscle mass after 50. If you're physically inactive, that loss can amount to as much as 3% to 5% each decade. A well-structured weight-training program can help boost not only your metabolism, but your strength and function, too.
   
   
2. Exercise right. Another fact of aging is that our joints start to show — and feel — wear and tear and may be more easily injured. Consider trading in some high-impact exercises for those that are gentler and kinder to your body. That might mean walking on the treadmill rather than running or alternating between the two. Better to be realistic about your abilities than give up exercising altogether because of pain or injuries.
   
   
3. Include plenty of produce in your diet. Fruits and veggies pack in valuable nutrients, which fill you up with less fat and calories than many other foods. Make sure to include them at every meal and fill half your plate with them. And, they can even satisfy a sweet tooth (think berries, watermelon) at a much lower calorie count than a cookie can.
   
   
4. Remember breakfast. Did you grow up hearing that breakfast is the most important meal of the day? Research doesn’t always support this, but making healthy choices in the morning can set the tone for the day, and decrease the chance you’ll overeat later. Plus, it helps maintain healthy blood sugar levels and boosts your energy.
   
   
5. Concentrate on cooking right. Look for ways to cut the extra fat and calories, like grilling, baking and broiling rather than sautéing or frying. And remember, olive and other oils may be healthy, but 1 tablespoon contains roughly 120 calories, so use them sparingly.
   
   
6. Get enough sleep. Blame the hunger-regulating hormones — ghrelin and leptin — for the weight gain that can result from skimping on sleep. That's because not getting enough sleep throws them out of whack and can cause you to overeat, crave foods that are high in calories and fat, and miss signals from your brain that you’re full. And then, there's the more obvious: sleep deprivation robs you of energy, making it more likely you'll be slogging through the next day.
   
   
7. Keep your stress in check. Constant stress can make you gain weight. Research shows that people with higher levels of the stress hormone cortisol can have more abdominal fat and higher body mass indexes.