Is there a “best diet” to follow? Johns Hopkins cardiologist Dr. Roger Blumenthal answers this question and more.

Q: What foods are good to boost your metabolism?

A: I do not believe in relying on a specific type of food to boost metabolism. More important, people should try to increase their metabolism by increasing physical activity. The muscles of the body are the engines that burn calories, and using them will burn more calories.

Q: How do I prevent bloating while I’m trying to eat healthy and lose weight?

A: There can be many reasons for bloating; constipation is one that comes to mind. This can often be helped by increasing fiber in the diet and by drinking more water or other low-calorie liquids. However, for weight loss, try to avoid high-calorie drinks like soda or other sugar-sweetened beverages. Bloating can also be caused by certain foods. Everyone knows about beans, but others that cause bloating include broccoli, kale and cabbage.

Q: What is the best diet?

A: The best diet is the one that works for you. However, as your question suggests, we really have not figured that out yet; it may vary from person to person. There are many choices but it seems like a well-balanced diet with carbs, fat and protein is a good, healthy choice.

We have done a few studies suggesting that a low simple carbohydrate approach can be effective and safe in terms of blood glucose, insulin and cholesterol levels, and people lost a moderate amount of weight. The key for each person is finding a diet that they enjoy, that is easy to follow, and that can be sustained over time to avoid regaining weight.

Also, it is important to increase daily physical activity. Many studies have shown that physical activity is critical to help keep the weight off over time.

Q: I want to keep my size but tone my body. I know I need to exercise, but I'm not sure where to start. Also, what foods should I eat?

A: Exercise guidelines recommend a combination of aerobic activities like walking or cycling and also resistance training using weights, resistive bands, or calisthenics. It is the resistance exercise that will help to maintain your muscle tone and prevent muscle loss as you get older. You do not have to eat anything special to maintain muscle tone — just do the exercises.

Q: I have heard that juicing is bad because it removes fiber. Is that true?

A: This is one of the downsides of juicing. You are leaving one of the key components of the fruit behind — the fiber. In addition, the juice is very highly concentrated with sugar. Overall, this is likely to be less filling and therefore, many people end up increasing their daily calories if they "over"-juice. It is better to eat the apple whole, including the skin, rather than squeeze it and just drink the juice.

Q: Are there specific fruits I should avoid if I am trying to lose weight?

A: Fruits can be a double-edged sword in a weight loss diet. Though they contain many healthy nutrients, they are often very high in sugars. Therefore, eating too much fruit can make it difficult to lose weight and may even lead to weight gain.

For example, a banana has 100 calories and about 27 grams of carbohydrates. An apple has about 115 calories and 30 grams of carbohydrates. Eating just two bananas and two apples a day would provide more than 100 grams of carbohydrates. You can do the math, but it becomes difficult to lose weight if the number of carbohydrates starts creeping over 100 grams per day. A well-balanced diet with carbs, protein and fat is a more sensible approach for most people.