A balanced diet of not-too-large portions is necessary to maintain a healthy weight -- preventing the heart risks of obesity. It is difficult for about a billion people worldwide to say enough is enough -- and 300 million obese continue to stuff.

Maybe these people would be most benefited by the new appetite suppression -- nesfatin-1, the molecule responsible for making us feel full and satisfied. Recently discovered in the hypothalamus of the brain by Japanese researchers, nesfatin-1 proved to block appetite and thus induce weight loss in lab rats. Conversely, the rats ate more and gained weight when the molecule was blocked. Researchers say the discovery of nesfatin-1 could be the first step in successfully treating and preventing obesity.

Excess weight gain and obesity -- dangerously high risk factors for heart disease -- can be prevented by simply reducing portion sizes at meal times. Many studies have shown that portion sizes are vastly misunderstood -- as an entire plate seems to be the logical indicator of how much to eat at a meal.

Here are some easy portion-sizing tips from Dr. Weil to help prevent over-eating at meal times:

• Cheese = one ounce, or the size of four dice
• Protein = three ounces, or no larger than the size of your own hand
• Beans, legumes = ½ cup cooked
• Starchy sides = a scoop the size of a tennis ball
• Dark leafy greens = one cup raw
• Cabbage family = one cup raw, ½ cup cooked
• Fruit = tennis ball size
• Whole grains = one slice of whole wheat bread, ½ cup cooked grains and pasta, one ounce cold cereal

And don't forget water! Six to eight 8 ounce glasses daily.

For the consumption-conscious, estimating the serving size of a piece of pizza, pie or cake can be challenging given their odd wedge-shape. Triangular food portions can now be accurately measured using a new adjustable wedge tool, according to a new study. It is important to watch portion sizes of foods such as these, as they can be higher calorie and lead to weight gain in excess -- which can become a risk factor for heart disease.

Tennessee State University researchers created an adjustable wedge to help determine the adequate serving size of triangular foods. They then tested this tool on subjects using pizza, cake and pie. When compared to the use of a ruler, the wedge was more popular by majority for its accuracy and ease of use. Unsurprisingly, the study found that participants frequently misjudged portion sizes -- underestimating the size of pieces of pie and pizza, and overestimating the size of a piece of cake.