The Truth & Reality Of Fad Diets


Fad diets are everywhere you look, and the fitness & health industry is absolutely booming right now. Every fitness guru wants a slice of the pie, but what are all these different diets being offered? High carb, Low carb, Low fat, Liquid diet, grapefruit diet, lemon detox, cabbage diet, juicing diet, i’ve even heard of a potato only diet.

It’s getting crazy out there.. and I want to shed some light on the facts about weight loss (within scientific literature off course), and expose the truth when it comes to fad diets once and for all.

Recent Research & Findings

Recent studies and controlled trials have found that regardless of your macronutrient ratio (carbs, fats & protein), your total caloric intake will be the determining factor between if you decrease body fat % or increase body fat %. An increased caloric intake (caloric surplus) is the scientific independent factor of why we have an obesity epidemic, without pointing the finger at fast food chains.

  • Calorie Surplus = Weight gain
  • Calorie Deficit = Weight loss
  • Total Caloric Intake = Determining factor

A controlled trial in a metabolic ward compared several diets having different macronutrient ratios, the finding were that the caloric restriction was the determining factor when it came to weight loss and not the macronutrient ratio. The study also concluded that high vs low carb dieting over a 6 and 12 week period led to the exact same conclusion with the determining factor falling back on the caloric restriction (calorie intake in a deficit, below maintenance levels).

Another trial in a metabolic ward found that with healthy individuals overeating for a period of 8 weeks, the caloric intake alone accounted for the increase in body fat %, however individuals with the higher protein intake found that the total weight and lean mass was increased.

So the determining factor with weight loss will always be energy balance which can either be obtained from eating in a caloric deficit or by increasing your activity level.

So Why Do People Still Get Results From Fad Diets?

Well there is no magic or hidden secrets which unleash some incredible amount of fat loss which most fad diets claim, it’s just simply not true. The reason why many fad diets do produce results, is because of the caloric restriction and a negative energy balance.

Many diets these days will focus on a restricted carbohydrate intake (ketogenic diet, Atkins, Paleo), and the reason these diets produce weight loss so quickly in the short term is because of glycogen stores in the muscles and liver being depleted, each gram of glycogen comes with around 3-4 grams of water.

So when you hear about people losing 3-6kg in the first 1-2 weeks of starting their diet, most of this weight is just excretion of water from the body. This also explains in trials why people are losing more weight initially in low-carb diets, and at later stages of the trials the differences are insignificant.

Thoughts and Opinions 

To be completely honest i’m not a huge fan of eliminating any macronutrient from a diet for extended periods, I believe a well balanced diet whether you’re wanting to drop body fat or add lean body mass is essential when addressing sustainability. And as the studies and trials have shown, energy balance is the fundamental key behind any diet.

However I have had  personal success with competition preparation on a cyclical ketogenic and high carb approach. The most significant findings with each approach was the high carb approach allowed me to retain more lean body mass while in a caloric deficit, and I also had significant improvements in retaining strength and performance with my training. Saying this I did have positive and significant results from the cyclical ketogenic approach, and I personally know many friends who live a low carb lifestyle and prefer this lifestyle.

So if you find that you get good sustainable results and prefer to adapt a low-carb / keto type lifestyle, then I say keep doing what you’re doing, just remember regardless of the macronutrient changes in any diet, the fundamentals will always apply (energy balance). If you’re starting a diet on the market which isn’t explaining the science behind all the hype, then be very careful because you’re putting your health at the hands of someone else.

If you’re unsure of where to get started on a training / nutrition program for sustainable results, I highly recommend looking into the 90 Day Fitness Model Challenge. Unlike most highly restrictive diets, this program will teach you the fundamentals of improving your metabolism, optimising hormones & recovery and applying a training program which fits your lifestyle.

Hope you enjoyed this post, reach out and leave a comment if I can help or answer any questions. 🙂


  1. Boden G, et al. Effect of a low-carbohydrate diet on appetite, blood glucose levels, and insulin resistance in obese patients with type 2 diabetes Ann Intern Med. (2005)
  2. McLaughlin T, et al. Effects of moderate variations in macronutrient composition on weight loss and reduction in cardiovascular disease risk in obese, insulin-resistant adults . Am J Clin Nutr. (2006)
  3. Leibel RL, et al. Energy intake required to maintain body weight is not affected by wide variation in diet composition Am J Clin Nutr. (1992)
  4. Golay A, et al. Similar weight loss with low-energy food combining or balanced diets . Int J Obes Relat Metab Disord. (2000)
  5. Noakes M, et al. Effect of an energy-restricted, high-protein, low-fat diet relative to a conventional high-carbohydrate, low-fat diet on weight loss, body composition, nutritional status, and markers of cardiovascular health in obese women . Am J Clin Nutr. (2005)