The misinformation about bananas on the internet is fairly extensive, especially relating to weight loss. There are some people out there actually trying to convince audiences that bananas are as bad to consume as cookies and french fries…I kid you not. If we look at the facts on bananas, we find a fruit with a low glycemic index, high in fiber and full of vitamins. They are one of the most nutritious and natural foods that help promote weight loss and help enhance immunity.
High in Critical Nutrients
Bananas are very high in vitamin B6 and also contain modest amounts of vitamin C, maganese, potassium and of course fiber. Sports enthusiasts appreciate the potassium–power delivered by this high energy fruit which many claim is as effective and even superior to sport energy drinks .
Since the average banana contains a whopping 467 mg of potassium and only 1 mg of sodium, a banana a day may help to prevent high blood pressure and protect against atherosclerosis.
The effectiveness of potassium–rich foods such as bananas in lowering blood pressure has been demonstrated by a number of studies. For example, researchers tracked over 40,000 American male health professionals over four years to determine the effects of diet on blood pressure. Men who ate diets higher in potassium–rich foods, as well as foods high in magnesium, had a substantially reduced risk of stroke.
A study published in the Archives of Internal Medicine also confirms that eating high fiber foods, such as bananas, helps prevent heart disease. Almost 10,000 American adults participated in this study and were followed for 19 years. People eating the most fiber, 21 grams per day, had 12% less coronary heart disease (CHD) and 11% less cardiovascular disease (CVD) compared to those eating the least, 5 grams daily. Those eating the most water–soluble dietary fiber fared even better with a 15% reduction in risk of CHD and a 10% risk reduction in CVD.
In addition to these cardiovascular benefits, the potassium found in bananas may also help to promote bone health. Potassium may counteract the increased urinary calcium loss caused by the high–salt diets typical of most Americans, thus helping to prevent bones from thinning out at a fast rate.
Eat a Banana Full Ripe or Yellow?
That depends on your taste buds and the health benefits you desire. According to Japanese Scientific Research , full ripe banana with dark patches on yellow skin produces a substance called TNF (Tumor Necrosis Factor) which has the ability to combat abnormal cells. The more darker patches it has the higher will be its immunity enhancement quality; Hence, the riper the banana the better the anti–cancer quality. Yellow skin banana with dark spots on it is 8x more effective in enhancing the property of white blood cells than green skin version.
It is a fact that nutrient content of fruits change slightly as they ripen. As a banana ripens and turns yellow, its levels of antioxidants increases. These antioxidants in ripe bananas protect your body against cancer and heart diseases. But while overripe bananas certainly have nutritional value, they also lose some benefits. In full ripe bananas with dark spots on skin, the starch content changes to simple sugars that are easier to digest but the glycemic index also increases.
Tumor Necrosis Factor(TNF) is a cytokine, substances secreted by certain cells of the immune system that have an effect on other cells. This is indeed helpful in fighting abnormal turmor cells in body. Research done on ripening bananas has proved that the levels of TNF induction increased markedly with dark spots on skin before the entire banana peel turned brown. The research concluded that the activity of banana was comparable to that of Lentinan, a chemical immunostimulant that is intravenously administered as an anti–cancer agent. So, ripe banana can act as an anti–cancer agent by stimulating the production of white blood cells in the human cell line.
Once bananas ripen fully, store them in the refrigerator to minimize further vitamin loss. Fresh bananas with brown patches on the skin are ripe enough to eat immediately. Make sure to avoid over–ripe bananas whose skin has turned brown or split open.
If you want to extend the freshness of a banana, the easiest way if you prefer to keep them at room temperature, is wrap plastic around the top or separate them.
What About The Carbs?
What About Them? You can still eat bananas regardless if you’re diabetic or on a weight loss program. All fruit has some carbohydrate, so you simply need to count them in your diabetes or weight loss meal plan. If you want to include bananas in your meal plan, become familiar with portion sizes and the number of carbohydrates in each.
Bananas vary quite a bit in size, so counting the carbs that they provide can be difficult. Below are some estimates for different sizes.
Extra small banana (6 inches long or less) — 18.5 grams of carbohydrate
Small banana (about 6–6 7/8 inches long) –23 grams of carbohydrate
Medium banana (7–7 7/8 inches long) — 27 grams of carbohydrate
Large banana (8–8 7/8 inches long) — 31 grams of carbohydrate
Extra large banana (9 inches or longer) — 35 grams of carbohydrate
Carbohydrates affect blood sugar and insulin levels. Slow–releasing carbohydrates are low on the glycemic index and can keep your blood sugar levels stable. Foods higher up the glycemic index will release their energy quicker, often causing the blood sugar levels to rise and fall rapidly. Following a low glycemic index diet helps control diabetes, weight gain and also plays a role in cardiovascular disease prevention.
Bananas are low on the glycemic index and release their energy into the bloodstream slowly. According to the GI Database , fully ripe bananas has a glycemic index of 51. This counts as a low glycemic index food, because its GI value is under 55. The maturity of your banana can have an effect on its GI rating. Slightly under–ripe bananas with green sections remaining have been calculated at 42 and over–ripe bananas with brown flecks have a GI of 48. This is not a huge difference, but it is something you might like to be aware of.
The Morning Banana diet was developed by Hitoshi Watanabe, who studied preventive medicine in Tokyo, and his pharmacist wife, Sumiko. The diet has since gained popularity by word of mouth, web sites, TV shows, magazine articles, and a book written by the Watanabes.
The Morning Banana Diet is a super simple plan. For breakfast, you have only bananas and room–temperature water. Then, you can eat whatever you like for lunch, dinner, and snacks, as long as you don’t eat after 8 p.m. The only restrictions: No ice cream, dairy products, alcohol, or dessert after dinner, and the only beverage you may have with meals is room–temperature water. One sweet snack is allowed midafternoon.
Different versions of the Morning Banana Diet tout varying explanations of exactly how bananas work to promote weight loss. One theory suggests that certain enzymes in bananas speed up digestion and elimination, causing rapid weight loss in some people.
Eating bananas is only part of an overall lifestyle change– including a healthy diet, cardiovascular exercise and strength training — that can result in effective weight loss. Eating bananas should not be the sum of your weight–loss plan, but rather one small part of it.
Bananas, along with most fruits have long been a part of healthy diets and weight loss plans. But while they are nutritious, they don’t have any special weight loss properties on their own.
To lose weight, you need to be physically active and control calories. And to stay healthy, you should choose healthy foods.
The truth is, there are no bad fruits, just poor lifestyle choices and often a misunderstanding of how to use fruits to your advantage in any diet. Anytime someone tells you fruit is bad for weight loss, disregard it. There really are no bad fruits, just good or bad diets.
Read the full article here: http://preventdisease.com/news/13/100413-Why-Bananas-Are-Good-For-Weight-Loss-Immunity.shtml 
Natasha Longo  has a master’s degree in nutrition and is a certified fitness and nutritional counselor. She has consulted on public health policy and procurement in Canada, Australia, Spain, Ireland, England and Germany.