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  • Susie Csorsz Brown

Fad diets: the good, the bad the ugly

A fad diet or diet cult is a diet that promises weight loss or other health advantages, such as longer life, and usually relies on pseudoscience rather than science to make many of its claims. In many cases, the diet is characterized by highly restrictive or unusual food choices. Do they work, do they help you to lose weight? Maybe. Will the weight stay off? Well, if the diet were possible to maintain, then maybe. But so much depends on you. So much depends on your activity level. So much depends on … so many variables.

Many fad diets are so highly restrictive, even going so far as to omit entire food groups. Is this a diet that is sustainable? Not really. Below I list a brief description of the more popular fad diets, and some good and bad details about each. Going into the list, though, know this: weight loss happens in the kitchen. All of the exercise you do will help you build an amazingly strong body, but it will not greatly impact your numbers on the scale with one caveat: the more muscle you have on your body, the more metabolically active your body will be (read: it will burn more calories even in rest than would a body of completely identical structure and make-up with less muscle).


What is it? A diet composed of high-fat, low-carb (ketogenic which means it puts your body into a state of ketosis, where through various biological processes, it will begin to reduce insulin levels and burn fat for energy instead of carbohydrates, and it will produce ketones for energy for your brain.)

Pro- A few studies have shown that the ketogenic diet may promote weight loss, lower blood sugar and increase insulin sensitivity in diabetics. There is also evidence that it can reduce seizures in children with epilepsy. And some studies suggest that the keto diet may slow the progression of Alzheimer’s disease, but the research on this is far from definitive.

Cons- Besides causing bad breath, uncomfortable digestive issues, and (generally) short term fatigue and weakness, as well as insomnia, a truly ketogenic diet is very hard to stick to. It’s a pretty extreme eating plan to follow all of the time, and while it may help with weight loss in a controlled study, it’s not so easy when you’re out in the real world trying to navigate office cupcakes, happy hours, dinner parties and more. A diet that makes you miserable just isn’t going to work for you. Also, it is very difficult to actually be in a state of ketosis (i.e., when your body burns through fat for energy instead of glucose). A few bites of bread here and sips of wine there, and boom—you are out and not reaping the benefits. The dreaded ketoflu —the initial period of the diet during which your body is adjusting to its new carb-free existence and symptoms like fatigue, brain fog and nausea are common, though generally once the ketoflu lifts, most feel more focused.


What is it? In its purest form, the paleo diet allows you to eat only those foods that humans ate when they first roamed the planet millions of years ago. In brief, you’ll be following a strict diet comprised only of foods that can be hunted and gathered. You’ll lose weight because any time you restrict entire food groups, your calorie intake tends to be lower. And whenever you burn more calories than you consume, you'll have weight loss.

The focus on lean protein, fruits, and vegetables over calorie- and sodium-rich processed foods can also contribute to weight loss, though this diet wasn’t created to be a weight loss diet. Includes lean meat, eggs (6 a week), fish, fruit, non-starchy veggies, nuts and seeds. No processed foods. No dairy. No cereal grains, no legumes, no starchy veggies, no sweets.

Pros– lots of vitamins and minerals, simple diet, no processed foods. Emphasizes exercise. Provides very structured meal plan and preparation. May provide a reduction in triglycerides, as well as weight loss, and better appetite management.

Cons– difficult to maintain. Diet can be boring. Can be expensive. High in fats. Preparation for meals can be bland and strict. Hard to follow if you eat out regularly.

Gluten-free diet

What is it? A diet that excludes foods containing gluten (wheat, barley, rye, triticale). The claimed benefits include weight loss, increased energy, and improved health. Foods that are allowed include: Fruits and vegetables; Beans, seeds and nuts in their natural, unprocessed form; Eggs; Lean, non-processed meats, fish and poultry; Most low-fat dairy products

Grains, starches or flours that you can include in a gluten-free diet include: Amaranth, Arrowroot, Buckwheat, Corn and cornmeal, Flax, Gluten-free flours (rice, soy, corn, potato, bean), Hominy (corn), Millet, Quinoa, Rice, Sorghum, Soy, Tapioca (cassava root), Teff

Pros– Good if you are a celiac (1% of the population) or have gluten sensitivity (6% of population).

Cons– significantly impacts fiber intake. Prepared gluten-free foods are often highly processed. Can risk low intake of iron, calcium, fiber, B vitamins. Often leads to weight gain. Many gluten-free products are higher in calories, fat, sodium and sugar because they need to enhance the flavor and texture to make up for the lack of gluten. Gluten free prepared products are often more expensive, and depending on your location harder to find. Gluten in found in many prepared foods and ingredients.

Mediterranean Diet

What is it? The Mediterranean diet is based primarily on whole plant-based foods, including vegetables and fruit, as well as whole grains, legumes and nuts, with small amounts of animal products (primarily seafood). Butter is replaced with heart-healthy olive oil, red meat is limited to no more than a few times a month, eating meals with family and friends is encouraged and wine is allowed (in moderation).

Pro- Studies suggest that this style of eating improves cardiovascular health and is associated with a reduced risk of cardiovascular death, certain cancers, certain chronic diseases and overall mortality. Extra bonus? It’s also easy to eat this way at many restaurants. Another bonus: Turns out women using the Mediterranean diet showed a 22 percent stroke reduction vs. a 6 percent drop in men, and the risk of stroke dropped mainly for women who were already at a high risk for heart disease.

Variations: THE DASH DIET

The DASH diet has been well researched and proven to lower blood pressure and cholesterol. This diet approach is very similar to the Mediterranean diet, with a focus on fruits, vegetables, whole grains, lean protein and low-fat dairy. Fatty meats, full-fat dairy and foods high in sugar and sodium are limited. Excellent option for those with high blood pressure or those who need to lower their cholesterol.

Cons- Not many unless you truly love butter.

Plant-based paleo (Pegan)

What is it? Similar to the Mediterranean diet in its emphasis on fresh over processed foods, plant-based paleo takes it a step further by eliminating dairy, gluten, refined sugar and vegetable oils. While straight paleo also eliminates grains and beans/legumes, this version allows them in small amounts. Reframing how you looks at meat (not as the main dish but as a condiment or side dish instead), eliminating highly processed and refined foods, and putting the emphasis on veggies as the star of the plate can help lower our risk of heart disease and many chronic illnesses. It also aids in weight loss and maintaining a healthy body weight over the long run.

Pro- good for health. Easy to find ingredients, but high-quality meats can be expensive.

Cons- Dairy and grains are controversial. Low-glycemic grains can be included.

80/20 Diet

What is it? You eat clean (read: low-fat, high-fiber, whole-grain, unprocessed foods) 80 percent of the time. The other 20 percent, you’re allowed (and even encouraged) to splurge.

Pro- 80/20 provides a good balance of eating nutritiously while also enjoying your favorite foods. Both of these things are important for any long-term lifestyle approach, since you're more likely to stick with a diet that allows for flexibility and enjoyment of your foods. It doesn’t consider any foods totally off-limits, and gives you a lot of control. As a result, you’ll likely develop a healthier relationship with food, since you aren’t depriving yourself of the stuff you really want to eat (and drink)

Con- it’s your responsibility to practice moderation. It’s important to think about the labels you are giving foods: ‘cheat’ foods or days implies that healthy eating is punitive; ‘bad’ foods versus ‘good’ foods creates guilt, … Important to not let the 20% become ridiculous. No bad foods, just inappropriate amounts.

The zone diet

What is it? 1/3 of your plate will consist of lean protein. This eating plan specifies that your calorie intake should be made up of 30% lean protein, 30% healthy fat and 40% high-fiber carbs. In addition, these foods are to be consumed as a prescribed number of “blocks” at meals and snacks (Each meal or snack on the Zone diet is carefully balanced so that you eat a small amount of protein along with your carbohydrates. This balance is thought to control insulin levels). The diet plan includes protein such as meat and poultry at every meal, plus whole grains, fruits, and vegetables. It limits milk and many dairy products, fruit juices, and many grain foods such as pasta and rice.

One of the ways the Zone diet is proposed to work is by reducing inflammation, which allows you to lose weight more easily.

Studies to date suggest the Zone diet can be effective for losing weight and reducing blood sugar, insulin resistance and inflammation.

Pro– emphasis on lean protein, and a decent make-up of food components.

Con– very rigid. Higher in fat and protein than generally recommended. Low calcium intake as well as fiber, folate, and vitamin C among other minerals.

The f-factor diet

What is it? The diet’s main pillar—the F in F-Factor—is fiber. The more fiber a food has, the more full you will feel after eating it, leading you to consume less throughout the day. Instead of focusing on what foods to avoid, F-Factor is about incorporating the right high-fiber foods into your diet. The diet focuses on combining lean proteins with high-fiber carbs, which are low in calories and keep you feeling full. These proteins and carbs include lean meats, veggies, fruits and whole grains. Fiber leads to greater satiety, less insulin secretion and more short-chain fatty acids. In a nutshell, upping your fiber should lead to weight loss. That, plus an emphasis on eating whole foods in moderation, makes F-Factor a sustainable healthy-eating program that doesn’t rely on gimmicks or too-good-to-be-true promises.

Pros- Able to dine out and drink moderate alcohol. You can eat carbs! Fiber is good for maintaining blood sugar levels, high cholesterol levels.

Cons- It’s a lot of fiber so might cause some GI discomfort in the beginning. Eating a lot of carbs can increase your appetite.

Fruitarian Diet

What is it? Adopting a fruitarian diet doesn’t mean you eat only fruit. Instead, diet descriptions say raw fruit should make up no more than 75 percent of foods consumed. It’s best to keep their fruit intake to no more than 50 percent to avoid any nutritional imbalances.

While these types of restrictive diets may help you lose weight in the short term, in the long run they’re unhealthy.

Pros- lots of vitamins and minerals.

Cons- very restrictive. Any diet that focuses on one food or food group (such as Fruitarian diet) is not well-balanced. No matter how nutritious a single food or food group is, our body needs a variety of nutrients for good health. In such a diet, it would be hard to get enough essential nutrients like B12, essential fatty acids like omega-3, iron and protein. And a lack of these nutrients can lead to a variety of problems, such as lethargy, anemia and decreased immune function. High in sugars.

Flexarian Diet

What is it? A blend of the words ‘flexible’ and ‘vegetarian,’ this diet does just that—it allows for flexibility with your approach to vegetarianism. The diet encourages people to follow a mostly plant-based but does not eliminate meat products entirely (instead, it aims to reduce meat and saturated fat intake). It's a great way to eat more fruits, vegetables, nuts and legumes, which are important for overall heart health, and also provides a more realistic approach for long-term success. Exercise is strongly encouraged. ‘the world is your gym’

Pros- Nothing is off-limits, but the goal is to add more plant-based foods. Best to aim for 5 days or more of meatless. It’s important to watch what you eat. Tends to be lower in fat, and help with health conditions like high blood pressure, diabetes, and heart disease.

Cons- none really

Intermittent fasting

What is it? It’s a regular period of fasting (aka, not eating) followed by a period of normal food consumption. The duration and frequency of the fasting periods vary, depending on the program the dieter is following. Some methods involve fasting until noon every day, some involve fasting for 24 hours once or twice a week, and others involve eating only one large meal per day. The idea is that by limiting your calorie intake occasionally instead of day in and day out, you’ll lose weight while still getting to eat the stuff you love.

Pro- (?) Proponents of the diet also maintain intermittent fasting can also help reduce cholesterol, inflammation, and blood pressure, reduce the risk of developing type 2 diabetes and prevent insulin spikes.

Con- Overall, it steers people away from tuning into their natural feelings of hunger and fullness, by telling them when they can eat.

The carnivore diet

What is it? Eating only animal foods (including eggs and some dairy, although the latter is limited. Just meat, seafood, eggs and a little bit of butter (grass-fed) and cheese. You can also consume some zero-calorie foods like coffee and spices.

Pro- this diet is very easy to follow in the sense that you don’t need to count calories, weigh your food or time your meals. And like with the ketogenic diet, you will probably lose some weight since you’re eating a lot of protein and fat but very few carbohydrates. Proponents say that the diet reduces inflammation, lowers blood pressure and increases mental clarity.

Con- The lack of dietary fiber in an all-meat diet is likely to wreak havoc on the bacteria in our colons, known as the microbiome. Growing evidence suggests that in the absence of adequate fiber, the bacteria in the colon consume and thin the protective mucus lining, which then leads to impaired immune function and inflammation.

Microbe diet

What is it? A microbiome diet is about creating an environment in which the good kind of bacteria can thrive, leading to better digestion, overall health and weight loss.

The first phase (which lasts 21 days) involves using diet to remove bad bacteria and increase good bacteria while the second phase (four weeks) is about giving your metabolism a boost. The final step in the plan teaches how to continue improving your gut health for life. Includes Non-starchy fruits and vegetables, lean protein, healthy fats and fermented foods like pickles and kombucha. Other important parts of the diet including taking probiotics and eating plenty of fiber. in general, you’ll want to avoid processed foods, sugar, eggs, soy, gluten, dairy and yeast. And on the Microbiome Diet, even foods like dried fruit, brown rice, potatoes and peanuts are off-limits because of their high sugar content.

Cons– so many things

The HCG Diet

What is it? Any diet that severely restricts calories or requires the addition of hormones [the HCG Diet involves injections of human chorionic gonadotropin] is not a healthy diet. The extremely low-calorie goal (500 per day) can cause the resting metabolic rate to slow and make it extremely difficult for people to maintain weight loss.

Cons– so many things

Tapeworm diet

What is it? It sounds crazy, but some people are intentionally swallowing a parasite (in the form of a tapeworm egg in a capsule) in the hopes of dropping pounds. This is an absolutely terrible idea and can have so many negative side effects, from diarrhea and nausea to headaches and general weakness. What's more, the worm can move to other parts of your body and attach itself to other organs, causing even more problems. Do not attempt!

Cons- so many things

So, then what does a healthy diet look like?

  • Eat breakfast every day and don’t skip meals.

  • Eat a variety of foods to ensure that you get all of your daily nutrients. Colorful diet is better (naturally occurring). Pay attention to WHAT you eat. Pay attention to WHY you eat. Practice portion control. Eat the foods you love, but in portions that are healthy. ‘All things in moderation is a key’ concept.

  • Watch what types of fat you consume. Do not eat any trans fats. Trans fats come from partially hydrogenated oils and are found in many fried and baked goods. Read nutrition labels as you grocery shop. Limit your daily intake of saturated fat and sodium. Try to eat healthy fats instead of opting for a strict low-fat diet. The latter typically is higher in carbs.

  • Limit the amount of sugar in your diet. High-sugar foods often are high in calories and low in nutrients. They also can lead to inflammation in your body. Avoid empty calories.

  • Limit liquid calories by avoiding soda and alcohol. Choose whole fruits instead of juice. Drink plenty of water every day.

  • Watch the size of your portions. Use the nutrition label to determine the correct serving size.

  • Exercise on a regular basis. Pick an activity that you enjoy. Aim for 30 to 60 minutes, 4 to 6 times per week.

  • Be more physically active in your daily life. Park further away from the door and take the stairs when you can. Get a pedometer or step counter and work toward a goal of 10,000 steps per day.

Friends, put your effort into creating a healthy diet for yourself. Invest your energy into finding healthy ingredients and recipes that you love. Find a few favorite fitness routines. Give yourself these gifts, and it will benefit you far more than a restrictive diet.

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