Weighing yourself too often can cause you to obsess over every pound. Penner recommends stepping on the scale or putting on a pair of well-fitting (i.e. not a size too small) pants once a week. “Both can be used as an early warning system for preventing weight gain, and the pants may be a better way to gauge if those workouts are helping you tone up and slim down.” [Tweet this tip!]
Here, too, body size is the main difference between the needs of males and females. Despite all the hype about high-protein diets, our protein requirements are really quite modest — only about a third of a gram per pound of body weight. For a 125-pound woman, that amounts to about 42 grams, for a 175-pound man, 58 grams. That's a tiny difference, just about half an ounce a day.
Sugar is a source of calories, not nutrients. Consuming too much sugar can lead to weight gain and tooth decay. Contrary to what many people think, there is no evidence linking high-sugar diets to hyperactivity or diabetes. However, high-fructose corn syrup, found in most processed foods, is linked with obesity, and obesity increases your risk for developing diabetes and other conditions.
Both your nutritional needs (the food and water) and your metabolism (how fast your body converts food to energy) change at this age. Your metabolism gets slower. Women lose about half a pound of muscle per year starting around the age of 40. That makes losing weight even more difficult. Some of the changes women experience are due to decreased hormones, reduced activity level, and medical conditions.
It doesn't matter how many pushups you can do in a minute if you're not doing a single one correctly. “There is no point in performing any exercise without proper form,” says Stokes, who recommends thinking in terms of progression: Perfect your technique, then later add weight and/or speed. This is especially important if your workout calls for performing “as many reps as possible” during a set amount of time. Choose quality over quantity, and you can stay injury-free.

Most experts recommend 1,300 mg of calcium a day for girls aged 9 through 19. Natural sources of calcium, such as low-fat dairy products, are the smartest choice, because they also contain vitamin D and protein, both required for calcium absorption. Milk, yogurt, and cheese contribute most of the calcium in our diets. Some vegetables are also good sources, including broccoli, kale, and Chinese cabbage. Many foods are supplemented with calcium, including some brands of orange juice and tofu. The daily intake for Vitamin D is 600 IU per day for most children and healthy adults.

As the table above shows, some of the best sources of calcium are dairy products. However, dairy products such as whole milk, cheese, and yogurt also tend to contain high levels of saturated fat. The USDA recommends limiting your saturated fat intake to no more than 10% of your daily calories, meaning you can enjoy whole milk dairy in moderation and opt for no- or low-fat dairy products when possible. Just be aware that reduced fat dairy products often contain lots of added sugar, which can have negative effects on both your health and waistline.
As the science of nutrition continually evolves, researchers recognize that nutrients needed to maintain a healthy lifestyle must be tailored to the individual for maximum effectiveness. Recognizing that people are not all alike and that one size does not fit all when it comes to planning and achieving a healthful diet, the Institute of Medicine's dietary guidelines, titled "Dietary Reference Intakes for Macronutrients," stress the importance of balancing diet with exercise and recommends total calories based on an individual's height, weight and gender for each of four different levels of physical activity.
In the past, women have often tried to make up deficits in their diet though the use of vitamins and supplements. However, while supplements can be a useful safeguard against occasional nutrient shortfalls, they can’t compensate for an unbalanced or unhealthy diet. To ensure you get all the nutrients you need from the food you eat, try to aim for a diet rich in fruit, vegetables, quality protein, healthy fats, and low in processed, fried, and sugary foods.