Keto, Whole30, Intermittent Fasting & Everything In-Between: The Pros & Cons of Popular DietsDec. 23, 2020 - Amanda Beaver
With the new year comes the desire for new beginnings and a fresh start. We may hear our friends, coworkers and family talk about new diets they're planning to try.
We also see countless Facebook articles about the latest eating trends and weight-loss strategies, and with all this conflicting information it can become difficult to know what we should even be eating.
Ultimately, there are benefits and drawbacks to every diet, so let's cut through all the noise and go straight to the pros and cons of some of the most popular ones.
The keto diet
Restricted foods: beans, bread, rice, pasta, sweets, potatoes, corn, many fruits, milk
The pros of the keto diet:
- Can reduce hemoglobin A1c and blood glucose1
- The restriction of many food groups may lead to weight loss2
- May increase HDL cholesterol (the good kind) and reduce triglycerides1
The cons to the keto diet:
- Restricts many foods, making it difficult to sustain2
- Cannot "cheat" — this will take you out of nutritional ketosis and may lead to detrimental swings in blood sugar and lead to blood vessel damage3
- Can increase LDL cholesterol2
- May be difficult to obtain certain nutrients2
The paleo diet
Restricted foods: grains, beans, cheese, milk, peanuts, soy foods (including tofu), processed foods, artificial sweeteners, refined sugars, some oils
The pros of the paleo diet:
- Focuses on many nutritious, unprocessed foods like fruits, veggies and proteins4
- The restriction of many food groups may lead to weight loss4
- May provide beneficial nutrients like vitamin C, potassium and fiber
The cons of the paleo diet:
- Restricts nutrient and fiber rich foods such as beans and whole grains4
- Prohibits prominent cultural foods such as rice and lentils4
- Research is inconclusive on whether it helps people with type 2 diabetes1
- May be difficult to obtain calcium for bone health4
- Can be expensive4
Restricted foods: grains, beans (except peas), cheese, milk, peanuts, soy foods (including tofu), artificial sweeteners, added sugar, some oils, alcohol, honey, maple syrup and even treat foods made with approved ingredients
The pros of Whole30:
- Focuses on nutrient rich whole foods like veggies, fruits, and proteins
- Allows people to mindfully add foods back into their diet after a 30 day period5
- Following the diet's protocol for 30 days may lead to weight loss due to the restriction of many foods
The cons of Whole30:
- Very restrictive, which may make eating out or socializing difficult
- May be difficult to get adequate calcium for bone health
- Restricts many cultural foods
- May be time intensive due to food label reading, meal planning and meal prep5
Whole30 also recommends limiting snacking.5
The whole foods, plant-based diet
Restricted foods: meat, poultry, dairy, eggs, cooking oils, juices, refined grains (white bread, pasta and rice)
The pros of a whole foods plant-based diet:
- Focuses on nutrient and antioxidant rich veggies, fruits, beans, grains and nuts6
- Restricts many foods, which may lead to weight loss7
- Shown to reduce blood pressure and LDL cholesterol6
The cons of a whole foods, plant-based diet:
- Highly restrictive, making it difficult to eat out or at social gatherings
- May be difficult to get enough omega-3 fats, protein, vitamin B12, zinc, iodine and calcium7
- Requires knowledge and deliberate meal planning to obtain all the necessary nutrients7
Restricted foods: practice fasting days or reduce the timeframe for eating, rather than the restriction of specific foods
There are many different intermittent fasting protocols, with some lacking support from scientific research.8
The pros of intermittent fasting:
- No restricted foods
- May improve glucose control and insulin resistance8
- May lead to weight loss8
The cons of intermittent fasting:
- May lead to intense hunger and side effects like fatigue, irritability and difficulty concentrating9
- Can lead to overeating during the time frame when eating is allowed9
- Does not purposefully encourage nutritious foods like veggies, fruits and proteins
Restricted foods: typically, all foods except juices and maybe a few foods containing protein
The pros of a juice cleanse:
- Veggie and fruit juices can contain antioxidants and vitamins10, such as potassium, vitamin C and Vitamin K
The cons of a juice cleanse:
- Resulting weight loss will likely be from losing water weight, a lack of food in the GI tract and muscle loss
- Will likely result in a shortfall in many nutrients10 including protein, fat, B vitamins and calcium
- Juicing removes much of a fruit or vegetable's fiber10
- Can lead to hunger and fatigue10
So, which diet is best?
The major drawback of almost all of these diets is that they are very restrictive and difficult to sustain. While they are achievable for some time, almost all of us will encounter situations such as ordering takeout from a restaurant and busy schedules that wear away at our intentions.
What's important for anyone considering a diet to know is that losing a few pounds, stopping the diet, regaining the weight and restarting a few months later can lead to an unhealthy behavior pattern known as yoyo dieting or weight cycling. This is detrimental to our bodies because it leads to muscle and potentially bone loss.
Another major drawback is that many of these diets restrict entire food groups, making it difficult to obtain certain essential nutrients. For example, it may be hard to get enough calcium when following the whole30 or paleo diet as they restrict dairy foods and most grocery store almond milks.
Ultimately, trying a new diet every year that just ends up in regaining the weight we lost can take a toll on our mental health, too. Oftentimes, we may overeat when we finally allow ourselves to enjoy those diet-restricted foods again, feel guilt after doing so and then experience low self-esteem. But let me tell you — it is the diet, not you!
If you do decide to try one, first let your doctor know and consider meeting with a registered dietitian who can help make sure the diet is right for you and you get all the nutrients you need. Some medical conditions and medications make these diets unsafe, and none of these diets are appropriate for people with a history of an eating disorder, or, in my opinion, pregnant women.
- 1Nutrition therapy for adults with diabetes or prediabetes: a consensus report
- 2Advantages and disadvantages of the ketogenic diet: a review article
- 3Short-term low-carbohydrate high-fat diet in healthy young males...
- 4Cutting through the paleo hype: the evidence for the paleolithic diet
- 5The Whole30 Program Rules
- 6Evaluation of an eight-week whole-food plant-based lifestyle modification program
- 7Nutrient and food intake of participants in a whole-food plant-based lifestyle program
- 8The effectiveness of intermittent fasting to reduce body mass index and glucose metabolism...
- 9Potential benefits and harms of intermittent energy restriction and intermittent fasting...
- 10Body cleansing or nutrient depleting?