A "real world" study has found Mediterranean and intermittent fasting diets are more effective than paleo because they're easier to stick to long-term.
The University of Otago study, published in the American Journal of Clinical Nutrition in December 2019, found the Mediterranean diet was the easiest to stay on, with 57 percent of dieters still on the diet at the end of the year, closely followed by the fasting diet at 54 percent. However, only 35 percent of dieters stuck with the paleo diet.
The research found intermittent fasting – where participants ate about 25 percent of their usual calories two days a week, led to more weight loss compared to the other diets, with an average weight loss of 4kg lost during the year.
Those on the Mediterranean diet lost an average of 2.8kg and paleo dieters lost an average of 1.8kg.
Co-lead author Dr. Melyssa Roy, a Research Fellow in the Department of Medicine, said the study supported the idea there wasn't a single "right" approach to diet.
"In the real world, the one right way to lose weight and eat right is that you can find what suits you the best, and whatever diet is the best is the one you stick to," she said.
"If you choose something that suits you, and is basically a selection of healthy foods, and perhaps eating a bit less often, you can actually get real-world benefits and just live a normal life, and lose weight and see improvements in your health."
The study also showed expensive weight-loss products or on-going dietitian advice were not necessary to help with weight loss, she said. "You can actually just choose a particular way of eating and apply it to your own life."
The average weight loss in the study didn't sound like a lot but it was enough to have health benefits, she said.
"These people just literally got given advice on how to follow a diet then got left alone and then at least half of them actually managed to lose an amount of weight that from a medical point of view is clinically significant," she said.
Those on the fasting or Mediterranean diets also saw significant improvements in blood pressure and there were also reduced blood sugar levels with the Mediterranean diet.
The Mediterranean diet encouraged consumption of fruit, vegetables, whole-grain breads and cereals, legumes, nuts, seeds and olive oil with moderate amounts of fish, chicken, eggs and dairy and red meat once a week or less.
The paleo diet included less-processed foods with an emphasis on eating fruit and vegetables, animal proteins, nuts, coconut products, and extra-virgin olive oil. While "original" paleo diets strictly excluded all legumes, dairy, and grains, this study used a modified version including some dairy as well as up to one serving daily of legumes and grain-based food.
Co-lead author Dr. Michelle Jospe, a Postdoctoral Fellow in the Department of Medicine, said most of the 250 participants in the study (54 percent) chose the fasting diet, while 27 percent chose the Mediterranean and 18 percent the paleo.