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Ask the dietitian: The eating plan that's right for you

Your common questions answered

If you're looking to lose a few pounds or just feel better in your own skin, you've probably done your fair share of research about the best diets available to look and feel your best. The problem is, there is so much information out there, it can get confusing fast.

Let us help you cut through the hype of four big ideas in the diet world right now. The keto diet External Site, Mediterranean diet External Site, intermittent fasting External Site and the Whole30® program External Site.

Julie Enga, dietitian and team leader, employer consulting and well-being services, at Wellmark Blue Cross and Blue Shield, answers your questions about these latest trends.

Is intermittent fasting a good tool for weight loss?

The evidence is mixed and researchers disagree about what type of fasting works best for different people. Intermittent fasting typically involves either eating very few calories on certain days, or eating only during certain hours of each day. Fasting is a lifestyle change that requires discipline, so you should consider if you can sustain this over a long period of time. Some people find it easier to have willpower for a short period of time rather than moderate willpower all the time. But there are downsides, including extreme hunger, headaches and possible drops in blood sugar. Before considering this type of diet for someone, I would want to understand their eating patterns, emotional thoughts/feelings around food and why they are interested in this diet. And, before you dive in, it’s important to talk to your doctor.

I’m considering trying Whole30. What are your thoughts?

Whole30 is a 30-day plan that eliminates anything processed, and even some whole foods in unprocessed forms, including grains, dairy, soy, legumes, sugar, certain preservatives and artificial sweeteners. It promises many benefits, including improved digestion, skin health and metabolism. Once the 30 days are completed, the foods can slowly be added back into the diet, depending on how the body responds.

If used as a 30-day “reset” after a period of eating unhealthy, such as the holidays, there can be some healthy takeaways from Whole30. When used as a plan for weight loss, however, I have concerns, especially when eliminating foods that are nutritious, such as grains or legumes.

In general, I’d say that focusing on whole, minimally processed foods is a great habit to put into practice. However, labeling a food as “good” or “bad” is risky. I have seen firsthand how shame can impact a person’s emotional relationship with food. Overall, I cannot encourage a plan that contributes or causes these types of problems.

My friend raves about the keto diet, and is now selling products to support it. Should I try it?

Keto diets are very low in carbohydrates, meaning you eat fewer than 50 grams of carbohydrates per day. The diet is rich in proteins and fats from meats, eggs, cheese, fish, nuts, butter, oils, seeds, and low-carb vegetables. When your body doesn’t have enough carbohydrates to burn for energy, it burns fat instead. This is called ketosis.

In my experience, the methods and results of keto diets vary. While it can help some people lose weight, it can be dangerous for others. Diets this low in carbohydrates have side effects, including flu-like symptoms such as fatigue, dizziness, irritability, headaches, nausea and muscle soreness. Also, because certain foods are eliminated, there is a risk of vitamin and mineral deficiencies, including antioxidants and fiber that promote a healthy gut. Plus, the high fat content combined with limits on fruits, vegetables and grains is a concern for heart health.

The bottom line is that, at least in the short term, the ketogenic diet can help with weight loss. However, because it is so restrictive, it is hard to follow long-term. You can’t go back to the way you were eating before and expect to keep off the weight.

Can you lose weight on the Mediterranean diet?

For long term success, the Mediterranean style of eating is a great choice. Notice I say “style” rather than “diet.” Mediterranean-style eating promotes minimally-processed foods and is really about what to include rather than what to exclude. Research has consistently shown that the Mediterranean diet is effective in preventing heart disease, increasing lifespan, and helps with healthy aging.

It features plant-based foods, including whole grains, vegetables, fruits, beans and other legumes, nuts, herbs and spices. Healthy fats, such as olive oil, are emphasized, along with a moderate consumption of protein. Red meat is limited to a few times per month. Red wine is optional in moderation. Daily exercise is essential, as well as the social aspect of eating meals together.

The only drawback is that for effective weight loss, you need to restrict calories. For example, portion sizes must be kept in check. Also, this style of eating won’t work if you simply add nuts or olive oil to your diet. It’s really a change in lifestyle, and I believe it’s a healthy and realistic style to follow for long-term health.

So, what's the bottom line when it comes to nutrition and weight loss?

The most important thing to understand is that it isn’t what you eat on any single day. It’s how you eat over time that makes a difference. There are no quick fixes. Often times, no matter how we go about weight loss, there is a lack of long-term commitment. Before you jump in, think not only about losing the weight, but maintaining the weight loss. It's also important to talk to your personal doctor before starting a new nutrition or fitness routine.

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