With summer in full swing and many people still going after that beach body; the hardcore promoting of fad diets is also in full effect. (Even though we all should know by now if you have a body and go to the beach… you already have a beach body).

“Turn your body into a fat burning machine!”

“Lose 10 lbs in a week!”

“FINALLY see the results you want!”

These are just some of the common claims of many of the diets out there. They all use the same types of marketing buzzwords and statements (whether they’re supported or not), and appeal to the large percentage of society looking to lose weight, and do it fast – fitting our society that is often looking for quick fixes or instant gratification rather than long-term success.

There are several issues with the mentality of relying on quick fixes and fad diets, but before we go into those reasons – what is a fad diet?

A fad diet is a diet that promises quick weight loss through, what is usually, an unhealthy and unbalanced diet (usually excluding one or more types or groups of foods). Fad diets are targeted at people who want to lose weight quickly. Some fad diets claim that they make you lose fat in a short period of time, but most of the time it’s water weight you’re losing. And if they’re extremely restrictive, fad diets can actually make it easier to re-gain weight (aka yo-yo dieting).

Here are the top four reasons to avoid Fad Diets

1. Fad diets can make it easier to gain weight back

One of the biggest failings of these fad diets, and something diet marketers obviously will not include in their promotions, is that they tend to make it easier to re-gain weight.

The typical claim of a fad diet, is that you will lose a large amount of weight in a short period of time.

What many people often don’t realize is that quick weight loss isn’t necessarily a good thing. They lose sight of the fact that weight often takes years to gain, so it makes sense that it should take some time to lose the weight.

Persistently eating too restrictively, and weight loss that happens too quickly can also have negative effects that actually can make it easier to re-gain weight. This is often referred to as yo-yo dieting or weight cycling. People often think that yo-yo dieting is their fault and a result of them not being able to stick to healthy changes, when really the factors below and more are at play.

One thing that tends to happen during fad diets is your body breaking down muscle for energy in the face of chronic calorie and/or carb/protein restriction. 1 This is not a good thing, because we want more muscle mass. The more muscle mass we have, the more calories our body burns at rest. Having muscle also gives that defined and toned look people talk about and tend to strive for.

Another thing that happens is called adaptive thermogenesis, also referred to as metabolic slowdown, or more commonly (and controversial) starvation mode. 2, 3 In basic terms, your body needs a certain number of calories per day just to live, breathe, and function (called your basal metabolic rate, or BMR). If we are consistently getting drastically less than our BMR (which many of these fad diets do, only providing roughly 600-1200 calories, which is too low for the majority of people), our body adapts by reducing the energy it expends each day (basically reducing its own metabolism, knowing it is getting less fuel). This is one huge factor that can make it easier to gain weight back, as it puts you more easily in a caloric surplus once you start eating more calories again, which is the leading factor in weight gain. 4

One more thing that long-term low calorie, and even very low carb diets can do, is contribute to hormone imbalances such as decreased thyroid output, increased cortisol output and decreased testosterone, all which can make weight loss more difficult. 5, 6

2. They make you feel bad

Research on cognitive dietary restraint (i.e. worrying and stressing out about food) shows that constantly and negatively fixating on what you eat (or don’t) can have the same unhealthy effect as dieting stringently. So, if a diet puts you in this mentality, it’s not a good thing.

Additionally, any diet that makes you feel like you’re being restricted, tends to end up backfiring in the end. A diet that causes you to completely eliminate foods that you enjoy (for no good reason), or that fit your lifestyle, can leave you feeling deprived and wanting to give up after a while. Many people also feel guilty when they stray from the diet, which leads to feelings of inadequacy and demotivation; leading to feeling overwhelmed and again, giving up.

Also, restricting your intake of calories and/or carbs too much can make you feel tired, sluggish, and hungry all of the time, and who wants that?!

3. They don’t set you up for long-term success

By taking an extreme measure, which is what many of these fad diets are, you are using a short-term solution that may give you some results quickly. But, these fad diets do not help you develop a healthier relationship food or lose weight in a healthy way that can be sustained for life. Instead, fad diets can have you losing and gaining the same 10 to 30+ pounds in a cycle, which has shown to have negative health effects of its own as the constant cycle of losing and gaining weight can put stress on the body.

4. They tend to be a waste of money

This is included as a reason to avoid these fad diets, and the reasons why they are a waste of money are all included in the three points above.

So, what’s the best thing to do?

Instead of looking for the next ‘miracle quick fix’ that is going to get the weight off as fast as possible, it’s important to invest in a program or professional that understands the science behind healthy eating, weight loss, and behavior change. A personalized program is key as well, because each and every person is different when it comes to their goals, metabolism, circumstances, etc.

Studies have consistently shown that one of the best diets, or ways of eating for overall health and weight loss, is the Mediterranean Diet. This way of eating is rather sustainable, and can fit with most lifestyles, even if you just choose to follow some of the concepts and modify it a bit.

Principles of a Mediterranean Diet:

• Emphasis placed on fruit, vegetables, whole grain bread, pasta, rice and cereal, potatoes, legumes (beans, peas, lentils, pulses, chickpeas, etc.), fish, nuts and seeds
• Include dairy products such as yogurt, Greek yogurt, cheese and milk
• Include eggs and chicken
• Olive oil as the principal source of fat, with other healthy fats such as olives, avocado and avocado oil
• Include herbs and spices such as; basil, thyme, garlic, rosemary, mint, cinnamon, pepper, etc., as well as lemon for flavoring
• Minimally processed, seasonally fresh, locally grown foods (as much as possible)
• Red meat rarely
• 1 glass of red wine per day
• Water as main beverage, coffee and tea are acceptable, but avoid sugar-sweetened beverages and fruit juices

For a realistic take on the Mediterranean diet, include other foods such as chocolate, baked goods, deep fried foods in small amounts, and as occasional treats rather than daily go-tos.

Remember that weight loss can and should be relatively slow, so aim to lose about 0.5-1 percent of your body weight per week. This helps to maintain muscle mass and minimize the adaptive metabolic responses to a lower calorie intake and resulting weight loss. Faster weight loss tends to result in more muscle loss without extra fat loss, as well as a reduction in metabolism.

1) Howarth KR, et al. Effect of glycogen availability on human skeletal muscle protein turnover during exercise and recovery. J App Physiol. 2010;109(2):431-438. Available from:
2) Rosenbaum M, and Leibel R. Adaptive thermogenesis in humans. Int J Obes (Lond). 2010 Oct; 34(1): S47–S55. Available from:
3) Doucet E, et al. Evidence for the existence of adaptive thermogenesis during weight loss. Br J Nutr. 2001 Jun;85(6):715-23. Available from:
4) Maclean PS, et al. Biology’s response to dieting: the impetus for weight regain. Am J Physiol Regul Integr Comp Physiol. 2011 Sep;301(3):R581-600. Available from:
5) Anderson KE, et al. Diet-hormone interactions: protein/carbohydrate ratio alters reciprocally the plasma levels of testosterone and cortisol and their respective binding globulins in man. Life Sci. 1987 May 4;40(18):1761-8. Available from:
6) Spaulding SW, et al. Effect of caloric restriction and dietary composition of serum T3 and reverse T3 in man. J Clin Endocrinol Metab. 1976 Jan;42(1):197-200. Available from:

About the Author

Felicia Newell is a Registered Dietitian (RD), Nutritionist, and Health Coach. She is also the owner of Sustain Nutrition, and helps clients from all around the globe fight through the misinformation in the online world, and master their health goals in a way that also allows them to also enjoy life. After many years in practice and through extensive research, Felicia knows that the ‘restrictive dieting’ technique never works long-term, and she takes the realistic approach of the ‘80/20 rule’, as well as working with clients to find the specific strategies that work best for them. You can download her FREE Meal Planning Starter Kit to help get you on your way to crushing your health and wellness goals.

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