25 Apr 2018 --- Diets seem to forever be evolving, with new diets being tipped every year to be the next “big thing.” As consumers are ever-more engaged with their health and losing weight remains a key concern, the continuous stream of weight-loss diets is set to continue. What does the future hold for current “trendy” low-carb diets, such as paleo and keto: are they fact or fad? NutritionInsight delves into the pool of paleo and keto.
“Old-school” diet programs such as the “the calorie restriction diet (approximately 1,500 kcal per day), the very low carb diet (less than 800 kcal per day) and the low fat diet (30 percent energy from fat) have lost popularity to low carb diets, high fat diets and paleo diets,” Dr. Roy McGroarty, an Infectious Disease Specialist and Humanitarian relief, recovery and development Program Manager, tells The World of Food Ingredients.
Keto and paleo have enjoyed immense popularity, with keto reaching number 3 on the diet trend list according to the “What's Trending in Nutrition” national survey. NutritionInsight spoke to Jennifer McDaniel, registered dietician and owner of McDaniel Nutrition, to find out more about the on-trend diets.
McDaniel asserts that both diets are based on a simple low-carb system, which in fact, has been an accepted and mainstream dieting approach for years – around for far longer than the paleo or keto hashtag.
In this fashion, the diets piggyback off the popularity of low-carb diets, but are “on-steroid” editions that successfully pique the interest of those already on the low carb bandwagon. “They push the accepted low-carb strategy, making it more appealing for some,” she says.
The diets have much in common, namely they both:
• Eliminate grains.
• Eliminate legumes.
• Eliminate refined sugar.
• Encourage non-starchy vegetables and leafy greens.
• Have an emphasis on healthy fats (animal fats, nuts, seeds, coconut oil).
• Encourage eating animal protein.
However, differences include that Keto does not restrict dairy and the paleo diet is not necessarily a low-carb, high-fat diet.
Keto, on the other hand, is based on this premise as this encourages the body to enter ketosis. The body reaches a ketogenic state when carbohydrate intake is so low that the body shifts to producing ketones to help fuel organs.
Typically, it is the metabolic process of using fat as the primary course of energy, instead of carbohydrates. This means that your body could break down its fat stores directly as energy, over slowly converting fat and muscle cells into glucose for energy.
The recommended macronutrient percentage to achieve this, by the keto diet, is 75 percent fat, 20 percent protein and 5 percent carbs.
Paleo, on the other hand, often referred to as the “caveman” diet, due to its base in the supposed eating patterns of the Paleolithic era. Simply, foods that were available before the agricultural revolution are recommended (think, hunter-gatherer diet: berries, fruits, meats, eggs, nuts).
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Humans are essentially social beings, and feeling part of a wider community can be key to the success or failure of a personal venture. Weight loss is such a venture, and McDaniels points out the importance of the huge social followings of keto and paleo, which have ultimately catapulted them to trendy status.
Concerning social media, the hashtag paleo provides a whopping 11.9 million hits on Instagram, and keto, a huge 5.8 million. “You can find any recipe for paleo and ingredients and feel part of a community in this way. So there is a large-spread following for these diets and this helps them last longer. If someone doesn’t feel supported, then the diet is harder to follow.”
“Dieting is culturally ingrained, and fad diets will continue to prevail as long as people equate thinness with personal and professional success. A study even found that with girls between 13-17, [approximately 75 percent] wish that they could be thinner. The social norm is that thin is more acceptable and you will be successful so people will continue to grab on to this,” and by inference, social media is a tool readily available to people to search for their next diet.
Furthermore, the diets have a strong foothold in certain communities. “Support is key to success. For example, the Paleo community is associated with the CrossFit world. When we have a diet that supported within a common community that share similar goals, we see better success. If someone doesn’t feel supported and or the diet is hard to follow, weight will being to creep and the diet lose popularity.”
The food industry has also responded to the popularity of the diets, with start-ups springing up that offer keto sports nutrition and snacks and Innova Market Insights notes that in the sports nutrition category, launches of paleo products increased 12 percent from 2015 to 2016 and 4.5 percent in the active health category. Outside of the sports fields paleo products also prospered, with product launches in the breakfast cereals category rising by 4 percent from 2015 to 2016, and launches of gluten-free products describing themselves as paleo rising by 9 percent.
What does science say?
The diets do have scientific backing, for example, a study published in Cell Metabolism, showed two independent mouse studies that provide evidence that a ketogenic diet improves memory in older animals, as well as the chances that an animal lives to old age.
“The animal studies provide proof of principle that ketogenic diets may have a positive impact on aging,” Jon Ramsey, Ph.D., a professor at the University of California Davis, told NutritionInsight. “However, it is essential to complete studies in humans to determine if ketogenic diets show efficacy for treating age-related diseases or improving function in late life.”
Other studies have detected the benefits of ketogenic diets on diabetes, obese patients and on high cholesterol.
However, experts point out that due to the extreme nature of the diet, longitudinal studies of keto and the state of ketogenesis on the body, are lacking.
Concerning the paleo diet, studies have consistently shown that the diet may benefit those who suffer from diabetes, especially if at an increased risk for cardiovascular disease. Also, a further study showed that overweight, menopausal woman could maintain weight loss on the diet due to the paleo diet having a high proportion of unsaturated fats. However, studies in this area are also somewhat limited.
Moreover, both the paleo and keto diet advocate cutting out entire food groups (Paleo eliminates dairy while both eliminate whole grains), which can lead to negative outcomes such nutritional deficiencies, boredom and an over focus on food. The British Association of Dieticians (BDA) assert that the limitation of whole food groups in a dietary plan is a sign of “fad” diets that should be avoided if healthy weight loss is the goal.
Furthermore, an array of research points to the vital health benefits that come from some eliminated food groups – such as the whole grains. A 2016 meta-analysis of 45 cohort studies, published in The BMJ, looked at the relationship between whole-grain consumption and the risk of various diseases including CVD and cancer. Researchers concluded that intake of whole grains is associated with a reduced risk of coronary heart disease, CVD, cancers, respiratory and infectious diseases, and diabetes.
This food group elimination can also lead to both the keto and paleo diets traditionally being heavy on animal protein and fat, which clinical studies increasingly suggest may not promote longevity or heart health.
McDaniels speculates that alternative dieting strategies that more revolve around lifestyle, meat-reduction and personalization will become popular. “There is definitely a growth in those interested in a more flexitarian, or plant-based way of eating. The food industry has definitely responded to this change in demand.”
Diets that eliminate food groups arguably stray into the category of “fad” diets that do not maintain long-term weight loss results, “The best diet is a plan that one can stick to for life. Food plans must be tailored and individualized – and fad diets don’t offer that flexibility,” adds McDaniels.
Such flexibility is personified in the growing area of “nutrigenomics,” “an understanding of how our own genes might affect how we metabolize food or how we lose weight.” By eating according to our genes, we will be able to personalize diets to genetic make-up, and “help provide validation for a certain way of eating to facilitate weight-loss.”
Essentially, if the main goal of following the keto or paleo diet is weight loss, then the diets will most probably deliver. However, the extreme notion of cutting out entire food groups, and in terms of keto, achieving an alternative longitudinal physical state may be difficult in the long-term for weight-loss maintenance and overall nutritional health.
Part two of this special report investigation on Diet Trends will bring Intermittent Fasting into the spotlight, and ask, is fasting the future?
By Laxmi Haigh
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