Intermittent Fasting, Mediterranean Diet, or Paleo, Which One Is Better?

If you're new to this blog, you'll find that I often start by defining the purpose of the post. In line with our title "Which One is Better?", it's essential to first define what "better" means. Today, we're exploring which of the three diets results in the greatest fat loss. While the answer might frequently be "it depends", I'll explore the various factors that determine the outcomes.

Let’s get geeky!

A research study from the University of Otago in New Zealand sought to answer this very question by analyzing the effects of three widely adopted diets.

Researchers compared Fasting, Mediterranean and Paleo

Here’s how it worked…

250 overweight or obese participants chose one of three diet plans: intermittent fasting, the Mediterranean diet, or a modified Paleo diet. They were given resources, a brief instruction session, and an exercise regimen. The primary aim was to observe what health benefits they might experience in a real-world scenario over a year with minimal external support.

A look at the different diets

1. Intermittent Fasting: Participants fasted two days a week, with a calorie cap of 500 for women and 600 for men. On non-fasting days, there was no specific diet but a recommendation for healthy eating.

2. Mediterranean Diet: Based on Harvard's Healthy Eating Pyramid, this diet focused on fruits, vegetables, whole grains, legumes, and olive oil, with limited meat.

3. Modified Paleo Diet: This approach prioritized fruits, vegetables, animal protein, and healthy fats. Some grains and legumes were allowed, making it a "modified" version of the traditional Paleo diet.

What the researchers found

- Intermittent fasting was the most chosen option, but the Mediterranean diet had the highest adherence.

- Intermittent fasters lost the most weight, whereas Paleo dieters lost the least.

- Intermittent fasters consumed fewer calories, even on non-fasting days.

- Paleo participants had the lowest intake of ultra-processed foods.

- Only two notable health improvements were observed: a decrease in systolic blood pressure for intermittent fasting and the Mediterranean group and a slight reduction in blood sugar for the Mediterranean group.

A curious observation was the gender disparity across the diet groups. The Paleo group had the highest percentage of women, and they also had the least weight loss. This leads to questions about whether gender differences played a role in the results.

What can we takeaway from this

1. Adherence to Restrictive Diets: The modified Paleo diet was the most restrictive and had the lowest adherence, indicating that flexibility in food choices might be key for many. So if you’re going to make a high calorie cake made out of almond flour, coconut oil and raw organic honey and proceed to eat 4 slices (yup, been there) you’re likely not going to see results.

2. Need for Support: Over time, without proper support, people tend to revert to old habits. The study revealed that after initial weight loss, many participants either plateaued or regained weight. Accountability matters, so if you are struggling, find someone you trust to support your goals.

3. Duration of Dieting: The reality is, dieting for an extended period is challenging. When these diets are viewed as temporary, the results are often fleeting. Another reason why I recommend my athletes to learn how to periodise their diets, more on this topic can be found here: Diet Periodization: What is it and how to do it.

4. Eating is a Continuous Journey: Quick fixes don't lead to lasting change. The real solution lies in long-term behavioral change. Another vote for accountability.

The study also highlighted the mechanics of intermittent fasting. The fasting days reduced participants' weekly calorie intake by 17%, leading to weight loss. However, fasting isn't a one-size-fits-all solution and should be considered carefully based on individual needs and health conditions.

Final takeaways

This study underscores the importance of tailored dietary guidance and the value of continuous support. For athletes, this research offers insights into how real-world adherence to these diets might look and emphasizes the significance of ongoing engagement to ensure lasting results.

Resoures

Jospe MR, Roy M, Brown RC, Haszard JJ, Meredith-Jones K, Fangupo LJ, et al. Intermittent fasting, Paleolithic, or Mediterranean diets in the real world: exploratory secondary analyses of a weight-loss trial that included choice of diet and exercise. Am J Clin Nutr. 2020 Mar 1;111(3):503–14.

Foster GD, Wyatt HR, Hill JO, McGuckin BG, Brill C, Mohammed BS, et al. A randomized trial of a low-carbohydrate diet for obesity.. N Engl J Med. 2003 May 22;348(21):2082–90.

Gardner CD, Kiazand A, Alhassan S, Kim S, Stafford RS, Balise RR, et al. Comparison of the Atkins, Zone, Ornish, and LEARN diets for change in weight and related risk factors among overweight premenopausal women: the A TO Z Weight Loss Study: a randomized trial.. JAMA. 2007 Mar 7;297(9):969–77.