nutrition: my thoughts on popular diets

discussing some of the pros, cons & my bottom line on popular diets

When the first of the year rolls around, we tend to hear A LOT about the different diets of the moment (and the old tried & true diets also seem to pop back up again!).

I hear from SO many of you asking for a breakdown on the different diets out there so I wanted to finally put together a post on it. I’ll work to update this post as new diets come out, and if you’d like a particular diet covered, let me know and I will add it!

Please note that the below is my opinion based on the education I received in the nutrition field and the research I have read to date. My comments on the pros and cons are just my quick hits (certainly not an in-depth look) and relate specifically to those looking to follow these diets for the purposes of weight loss or improving health.

If you’ve successfully followed one of the below diets that I may not strongly recommend and you feel great on it – more power to you! At the end of the day, that’s what matters. Ultimately, the decision to follow a particular diet should come down to whether or not it’s right and safe for you. This post is not an effort to tell you what to do or that what you’re doing is right or wrong. I simply want to show different sides of the picture as I see it, so you can make an informed decision. As always, I recommend working with an expert before embarking on any significant dietary change.

THE KETO DIET (FOR WEIGHT LOSS)

About the Diet:

The Keto Diet was initially developed as a way to treat children suffering from epilepsy. However, it’s now become a popular diet for weight loss.

The idea behind the Keto Diet is to put your body into a state of ketosis – an adaptation that allows humans to survive during long periods of famine.

I don’t want to go into too much of the science of it, but I want to just touch on the somewhat extreme nature of what needs to be done in order to reach a state of ketosis…so bear with me!

Our body stores carbohydrates we eat in the form of glycogen. When we need energy, our bodies break down glycogen to release energy (glucose) to our cells so we can utilize it. Note: energy from carbohydrates (glucose) is the preferred fuel by our bodies. When we’ve used up all those carb stores without replenishment, our bodies turn to the breakdown of stored fat for energy.

When fat is broken down, ketones are produced, which provide energy for the brain when fuel from carbohydrates is scarce.

In order to achieve a state of ketosis, one would need to fast or strictly limit carbohydrate intake (>20 to 30g per day…to put that in perspective, one slice of bread has about 12 grams of carbohydrate). Fat intake then needs to be increased to about 70% to 80% of total calories while protein intake is moderate (the reason for moderate protein being that some forms or protein can be converted to glucose by the body, pushing the body out of the ketosis state). As this was a diet developed to treat children with epilepsy, it was typically carried out under strict clinical supervision where labs, cognitive and other physiological function could be very closely monitored.

Pros:

• May provide a short-term decrease in hunger levels when compared with low-calorie diets
• May provide short-term weight loss
• May improve insulin sensitivity & glycemic control (though the mechanism is unclear)
• Likely encourages more home-cooking

Cons:

• Restricts entire food groups that provide numerous benefits to our bodies leading to the potential for nutritional deficiencies, boredom due to lack of variety, guilt associated with eating “off-limit” foods and a laser focus on food you’re not supposed to have
• Potential to experience the “keto flu” (symptoms such as lightheadedness, fatigue, headaches, nausea, and constipation due to rapid excretion of sodium & fluids as carbs are eliminated)
• Long-term effects of the diet are unclear
• If not followed correctly, may lead to muscle loss as the body attempts to break down protein to convert into glucose
• Likely hard to sustain long-term

The Bottom Line: Until long-term effects have been studied in greater detail, I think there are better options for those looking to do this diet specifically for weight loss. Ultimately, this diet limits or restricts whole food groups that provide numerous benefits, likely making long-term adherence difficult and leading to the potential for nutrient deficiencies. If you do want to follow this diet, do so with the help of a Registered Dietitian who can ensure you’re doing it appropriately, can recommend any needed supplementation and can regularly monitor cognitive and physiological functions.

THE PALEO DIET

About the Diet:

The premise behind the Paleo diet is that individuals eat in a way that is thought to mimic what early humans ate in order to be healthier, lose weight and curb disease (the idea being that our bodies are genetically predisposed to eat this way). Foods allowed on the diet are those that can be hunted, fished or gathered: meat, fish, shellfish, poultry, eggs, veggies, roots, fruits and berries. No grains, dairy, legumes (beans, lentils and peas), refined sugars or processed foods.

Pros:

• Emphasizes nutrient-dense food groups such as fruits, vegetables, nuts, seeds, and protein
• Focuses on whole, unprocessed foods
• Likely encourages more home-cooked meals

Cons:

• Restricts entire food groups that provide numerous benefits to our bodies leading to the potential for nutritional deficiencies, boredom due to lack of variety, guilt associated with eating “off-limit” foods and an all-consuming focus on restricted items
• Elimination of all dairy long-term has the potential to lead to calcium & vitamin D deficiencies if not appropriately supplemented
• Likely hard to sustain long-term

Bottom Line: The Paleo diet has positive aspects in that it promotes a diet high in fruit, vegetables, nuts, seeds and lean protein. The elimination of processed foods can also lead to health benefits (like increased home cooking, a reduction in excess fat, sugar and sodium, etc.). However, unless medically necessary, I would not recommend cutting out all dairy, grains and legumes as these provide necessary nutrients for the body and long-term restriction could lead to deficiencies. Again, if you’re interested in following this diet, work with a Registered Dietitian who can ensure it’s being carried out appropriately and you’re able to meet your specific needs.

WHOLE30

About the Diet:

Whole30 is an elimination diet that promotes fresh foods while eliminating anything processed. Dairy, all grains, sugar, soy, legumes, artificial sweeteners and certain preservatives are eliminated as well as the diet believes them to be linked to a variety of health problems.

Individuals are allowed three meals a day (snacks outside of planned pre/post workout are not encouraged). Meals are composed of a moderate amount of protein, fruits, vegetables, nuts, seeds, and fats (from oils, butter, coconut, and olives). At the end of 30 days, the eliminated foods can be slowly added back provided the body responds well upon doing so.

The promise is that by strictly following the plan for 30 days, individuals will see an improvement overall and in their digestion, metabolism, fitness and skin.

Pros:

• Emphasizes nutrient-dense food groups such as fruits, vegetables, nuts, seeds, fat and protein
• Focuses on whole, unprocessed foods
• Likely encourages more home-cooked meals

Cons:

• Restricts entire food groups that provide numerous benefits to our bodies and while nutritional deficiencies may not occur in the 30 days, you’re still looking at the potential for boredom due to lack of variety, guilt associated with craving or eating “off-limits” food and an all-consuming focus on the food you’re not allowed to have
• What is going to inflame one person is not necessarily going to inflame another and eliminating nutrient-dense foods simply because they’ve been labeled pro-inflammatory (when you’ve otherwise done well with them) isn’t the best course of action
• Sets up a mentality where you can “fail” by listening to what your body is asking for
• Likely hard to stick to / sustain

Bottom Line: The idea behind Whole30 is positive in that it puts the focus on whole, unprocessed foods, making more of your own meals (good for your wallet too!) and eliminating foods that seem to disagree with you or leave you feeling not so great. However, eliminating whole food groups can make a diet very difficult to stick to and can set you up to “fail” if you crave or enjoy one of those foods. An overly restrictive diet can also isolate you socially. If you’re concerned about a certain food or suspect something in your diet is causing you to feel less than stellar, I recommend working with a Registered Dietitian to pin-point what that food (or foods) could be. Together you can develop a plan on how to work around it while ensuring you’re getting the nutrients you need.

INTERMITTENT FASTING: Read my post here.

When it comes to a particular dietary pattern, the first thing I would advise you to ask yourself is “can I realistically incorporate this into my lifestyle?” If the answer is no, you likely want to find something that can. You may be able to stick to a restrictive plan short-term, but if it’s cutting out some of your favorite foods (especially if they’re nutrient dense options!) then it’s not realistic you’ll eat that way for the long haul. Additionally, if there’s NO flexibility to do things like enjoy a night out with your friends or spend time with your loved ones all because of your diet, that’s another red flag. I encourage you to think about food as something that fuels your body and helps it to function at its best. Categorizing foods as “off-limits” can often give those foods even more power, making you think of nothing else. Rather, let yourself enjoy a moderate portion of your favorite foods and balance it out with other nutrient-dense options that will give you energy and keep you going throughout the day.

I recommend aiming to include a wide variety of nutrient-dense foods such as whole grains, lean proteins, heart-healthy fats, fruits, vegetables and dairy. Listen to your body and let that be your guide. This eliminates the potential to associate food or eating with guilt or failure and instead puts the focus on fueling your body & meeting your needs as dictated by your hunger and fullness levels.

For many of us, this concept takes a lot of work and self introspection. We’re surrounded by dietary advice every day (from both qualified & unqualified sources) and as such, it may mean needing to shut out all those outside influences and work hard on reconnecting with your body and needs (more on this to come!).

disclaimer: the above are simply my opinions based on the research I have seen and read. ultimately, the decision to follow a particular diet should come down to whether or not it’s right for you. always consult an expert before embarking on any significant dietary change.

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