February, 2017 - Real Food Dietitians

By Tamzyn Murphy

BSc Med(Hons) Human Nutrition and Dietetics, RD

The Paleo diet, founded by researcher Loren Cordain (PhD), is based on what our caveman ancestors ate. It includes only the foods we’ve eaten for most of human history; which we’ve evolved to eat. Like Atkins, Paleo is a low carb, moderate protein, high fat diet. You’re allowed as much meat, fish, poultry, eggs, natural fat (e.g. butter, olive oil, avocado) and non-starchy vegetables as you like. Unlike Atkins, Paleo allows any other foods that our caveman ancestors ate, like any root vegetables, nuts, seeds and fruit. We only became dependent on farmed foods, like grains, legumes (beans, peas, lentils) and dairy, relatively recently – less than 500 generations ago – with the advent of agriculture. So our genes haven’t had much time to adapt to problem compounds in these foods, theoretically causing inflammation and weight gain.

Indeed, grains and legumes contain anti-nutrients (like lectin and gluten) which interfere with nutrient absorption, irritate intestinal lining (promoting leaky gut) and yield other toxic effects. Cereal grains, particularly wheat, are the worst.[i] So there’s a case to be made for limiting or even eliminating them. But legumes’ anti-nutrients are largely inactivated by cooking at high temperatures, which makes them relatively safe[ii]. Plus legumes contain numerous beneficial compounds.[iii] They’re also are an important protein source – particularly important for vegetarians, vegans and the poor; not to mention ethical and environment-friendly meat-replacements. There’s no evidence that legumes increase weight gain. Research shows that dairy doesn’t have inflammatory[iv] or weight promoting effects[v]. In fact it may do the opposite.

So, the theory behind Paleo is sound – eat whole, unprocessed food as much as possible. But including moderate amounts of dairy and legumes may offer more benefits than risks. Paleo loses points on the expense-front, and due to the lack of dairy you might want to supplement with calcium and vitamin D, unless you’re getting plenty of other calcium rich foods and enough sunshine.

References

[i] Cordain L. Cereal Grains: Humanity’s Double Edged Sword. Simopoulos AP (ed): Evolutionary Aspects of Nutrition and Health.Diet, Exercise, Genetics and Chronic Disease. World Rev Nutr Diet. Basel, Karger, 1999;84:19-73

[ii] Pusztai A, Grant G. Assessment of lectin inactivation by heat and digestion. Methods Mol Med. 1998;9:505-14

[iii] Bouchenak M, Lamri-Senhadji M. Nutritional quality of legumes, and their role in cardiometabolic risk prevention: a review. J Med Food. 2013 Mar;16(3):185-98

[iv] Labonté MÈ, Couture P, et al. Impact of dairy products on biomarkers of inflammation: a systematic review of randomized controlled nutritional intervention studies in overweight and obese adults. Am J Clin Nutr. 2013 Apr;97(4):706-17

[v] Abargouei AS, Janghorbani M, et al. Effect of dairy consumption on weight and body composition in adults: a systematic review and meta-analysis of randomized controlled clinical trials. Int J Obes (Lond). 2012 Dec;36(12):1485-93

By Tamzyn Murphy

BSc Med(Hons) Human Nutrition and Dietetics, RD

People across the globe are getting fat and desperate – a profitable situation for those peddling fad diets. Obviously conventional nutritional wisdom has failed us – eating fewer calories (particularly less fat) and burning more by exercising doesn’t cut through the flab. It appears that our will-power just isn’t strong enough to overcome the hunger that goes with this kind of advice. Authorities’ recommend that we base our eating on carbohydrate-filled food, with less than 30% of calories from fat and about 15-20% from protein. Much of these carbs come from refined starches and sugar, making our insulin levels skyrocket, which puts our bodies into fat-storage mode and makes us even hungrier. But before that sends you running into the arms of the latest diet, make sure you know which ones work and which are doomed to failure.

New Atkins Diet[i]

Atkins is a low carb diet – one of the stricter versions. You shouldn’t be hungry on this diet though and calories aren’t restricted. Most people think low carb diets are high in protein and low in fat. Thankfully this isn’t usually the case – fat keeps hunger at bay and the right types promote good health; while excessive protein could be dangerous. Low carb diets are typically high in fat (60% or more) and moderate in protein (about 25%). The aim is to keep insulin levels low by restricting carbs, thereby reducing hunger and fat-storage, and retraining the metabolism to burn fat instead of carbs. They’re great for weight loss. And recent evidence indicates they may also reduce heart disease, diabetes and metabolic syndrome risk.[ii] They’re particularly beneficial for those with insulin resistance or pre-diabetes.[iii]

There are four phases to the New Atkins diet – an updated version of Atkins. Phase 1 is really strict, allowing only 20g of carbs a day – mainly from low carb veggies. As you move through the phases you gradually increase the amount of carbs you’re allowed according to the “Carb Ladder” – adding nuts, seeds, low carb fruits, certain dairy products and some legumes. During this process you’re supposed to learn what your individual carbohydrate tipping point is – eat less carbs and you lose weight, more and you gain weight. By the end you should have lost all of your excess weight and know how to make this diet a permanent lifestyle fixture to maintain your weight and optimise health.

Critics claim the high fat content, particularly saturated fat, of low carb diets is bad for heart health but recent evidence refutes this.[iv] Others worry that excessive protein puts strain on the kidneys and leaches calcium from the bones, but the protein content of these diets isn’t typically excessive and there’s no evidence that it negatively impacts on kidney[v] or bone health.[vi] Where casual Atkins dabblers go wrong is they use it as an excuse to pass up on vegetables, gorge in processed food and deep fry everything.