Every weekday, a CNNHealth expert doctor answers a viewer question. On Friday, it's Dr. Melina Jampolis, a physician nutrition specialist.

Question asked by Courtney L. from Pittsburgh:

I am obese and have been working on losing weight for three years. I have been working with nutritionists and personal trainers instead of fad dieting. On the Web, I stumbled upon the Paleolithic (Paleo) diet. Is this lifestyle change beneficial despite the promotion of saturated fats and cholesterol?



Expert answer

Hi, Courtney. I applaud you for staying away from fad diets in an attempt to lose weight. Most fad diets are simply not sustainable long term, which leads to weight regain, and their impact on overall health has not been established.

Unfortunately, in my opinion, the Paleo diet falls into the fad diet category.

While there are many different versions of the diet with slightly different rules, the general principle of the diet involves eating foods that can be hunted and fished (meat, seafood - grass-fed, wild and organic are encouraged) or gathered (eggs, fruits, nuts, seeds, vegetables and herbs).

Dairy, legumes, salt, grains, refined sugar, processed oils, potatoes (including sweet potatoes) and alcohol are excluded from the diet.

Basically, this is a high-protein, relatively low-carb diet. The positive aspects of this diet are that it eliminates processed foods, a major source of added sugar, salt and fat in the American diet.

The diet also eliminates sugar and refined grains, both of which contribute to obesity and diabetes and can lead to increases in dangerous belly fat, which has been linked to heart disease, Alzheimer's disease and cancer.

In addition, the diet encourages a wide variety of fruits, vegetables, nuts (except peanuts, which are legumes) and seeds, all of which are an important part of a healthy, balanced diet.

The cons are:

1. The diet eliminates dairy, an affordable and widely available source of bone-building calcium (and vitamin D when dairy foods are fortified) and protein (yes, calcium can be obtained from greens and other foods, but it is more challenging to consume adequate amounts.)

2. The diet eliminates all grains, including whole grains, which are a good source of vitamins, minerals, antioxidants and heart healthy fiber, and foods such as beans, peanuts and sweet potatoes, all of which have numerous health-promoting qualities.

3. The diet is high in animal protein, which could lead to an excess intake of saturated fat, resulting in elevated cholesterol levels, an increased risk of heart disease and increased risk of certain types of cancer.

4. Finally, the diet can be expensive (grass-fed, organic meats and eggs are more expensive) and inconvenient due to the limitation of food choices, both of which make this diet less practical for the average person long term.

Overall, I would steer clear of the Paleo diet, but we can take away something from our ancestors by eating foods closer to their natural state (less processed), which are more nutrient-dense and digested more slowly by the body. In most cases, they lead to better hunger control, more stable blood sugar levels and weight loss if calories are reduced and exercise is increased (as it sounds like they are in your case).

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