With several weight loss diets available it can be difficult to know whether they are worth trying or even beneficial for your health. Some diets focus on reducing the amount you eat, whereas others emphasise on restricting the amount of calories or certain nutrients such as fats and carbohydrates you consume. Unfortunately no single weight loss diet will be suitable for everyone due to a number of reasons; however we have reviewed some of the current popular weight loss diets and the facts behind them;
The Paleo Diet
This diet is based on the concept that modern humans ought to be eating as our hunter gatherer ancestors ate. The theory behind the Paleo diet is that most modern-day diseases and health issues are related to the western diet and how we consume dairy, grains and processed foods. Therefore it empathises eating whole foods, lean protein, fruits and vegetables and nuts and seeds. Individuals should avoid processed foods, sugars, dairy and grains.
Numerous studies have found that following the Paleo diet can cause a significant amount of weight loss and a reduction in waist size, as dieters eat less carbs and proteins and consume fewer calories (1, 2, 3). Dieters also have a reduced risk of heart diseases (4, 5) however as the diet cuts out whole grains, legumes and dairy foods it ends up eliminating numerous nutritious and healthy foods.
The Atkins Diet
This is currently the most popular low-carb weight loss diet. It claims that you can lose weight despite eating as much protein and fat as you like, followers are only advised to avoid carbs as this can reduce your appetite. The diet has four phases, the first of which you are advised to eat under twenty carbs per day and the remaining phases ask dieters to slowly reintroduce healthy carbs back into the diet as the goal weight approaches.
Studies have found the Atkins diet can lead to faster weight loss (6, 7). Low carb diets such as the Atkins diet have also been found to reduce belly fat (8, 9, 10) as well as reducing the risk factors for diseases such as cholesterol, blood sugar and blood pressure (11, 12, 13).
The Ultra-Low-Fat Diet
The ultra-low-fat diet restricts the amount of fat that can be consumed to fewer than ten percent of consumed calories. Dieters will usually only consume plant based food and has a very limited intake of meat. 'The diet has been shown to be successful for weight loss in obese individuals (14), however is not suitable as a long term diet.
Benefits of this diet include a significant improvement in type two diabetics (15, 16) and an improvement in risk factors for heart diseases (17, 18). Unsurprisingly though the ultra-low-fat diet can create long term problems as fat plays an important role in the body such as building cell membranes and hormones. Due to the limited intake and variety of foods, this diet is very hard to follow for a long period of time.
This is more of an eating pattern that you follow in cycles between periods where you fast and eat. This diet does not restrict food, it just states when food should be eaten in order to restrict calories. Some of the most popular ways of intermittent fasting include;
- The 16/8 method – skipping breakfast and restricting eating to eight hours a day only
- The 5:2 diet – restricting intake of calories to 500-600 twice a week and eating like normal on the other five days of the week
- The warrior diet – eating a small amount of raw fruits or vegetables in the daytime and one main large meal at night
Intermittent fasting appears to be generally very successful (19) and causes less muscle loss than the standard calorie restriction diets. Dieters also experience a short term increase in metabolic rate (20) and a reduction in markers of inflammation, cholesterol levels and blood sugar levels (21, 22, 23).
To successfully lose weight and keep it off, a combination of healthy eating and exercise is always recommended. Remember when choosing a new diet routine for yourself, you should always look for one that you can foresee yourself sticking to in the future and always speak to your doctor before beginning a new diet plan.
To learn more about the good, the bad and the ugly of diets and nutrition, see our nutrition diplomas page.
- Lindeberg, S., Jönsson, T., Granfeldt, Y., Borgstrand, E., Soffman, J., Sjöström, K. and Ahrén, B., 2007. A Palaeolithic diet improves glucose tolerance more than a Mediterranean-like diet in individuals with ischaemic heart disease. Diabetologia, 50(9), pp.1795-1807.
- Osterdahl, M., Kocturk, T., Koochek, A. and Wandell, P.E., 2008. Effects of a short-term intervention with a paleolithic diet in healthy volunteers. European journal of clinical nutrition, 62(5), pp.682-686.
- Ryberg, M., Sandberg, S., Mellberg, C., Stegle, O., Lindahl, B., Larsson, C., Hauksson, J. and Olsson, T., 2013. A Palaeolithic‐type diet causes strong tissue‐specific effects on ectopic fat deposition in obese postmenopausal women. Journal of Internal medicine, 274(1), pp.67-76.
- Masharani, U., Sherchan, P., Schloetter, M., Stratford, S., Xiao, A., Sebastian, A., Kennedy, M.N. and Frassetto, L., 2015. Metabolic and physiologic effects from consuming a hunter-gatherer (Paleolithic)-type diet in type 2 diabetes. European journal of clinical nutrition, 69(8), pp.944-948.
- Genoni, A., Lyons-Wall, P., Lo, J. and Devine, A., 2016. Cardiovascular, metabolic effects and dietary composition of ad-libitum paleolithic vs. Australian guide to healthy eating diets: A 4-week randomised trial. Nutrients, 8(5), p.314.
- Santos, F.L., Esteves, S.S., da Costa Pereira, A., Yancy Jr, W.S. and Nunes, J.P.L., 2012. Systematic review and meta‐analysis of clinical trials of the effects of low carbohydrate diets on cardiovascular risk factors. Obesity reviews, 13(11), pp.1048-1066.
- Hession, M., Rolland, C., Kulkarni, U., Wise, A. and Broom, J., 2009. Systematic review of randomized controlled trials of low‐carbohydrate vs. low‐fat/low‐calorie diets in the management of obesity and its comorbidities. Obesity reviews, 10(1), pp.36-50.
- Volek, J.S., Sharman, M.J., Gómez, A.L., Judelson, D.A., Rubin, M.R., Watson, G., Sokmen, B., Silvestre, R., French, D.N. and Kraemer, W.J., 2004. Comparison of energy-restricted very low-carbohydrate and low-fat diets on weight loss and body composition in overweight men and women. Nutrition & metabolism, 1(1), p.13.
- Krebs, N.F., Gao, D., Gralla, J., Collins, J.S. and Johnson, S.L., 2010. Efficacy and safety of a high protein, low carbohydrate diet for weight loss in severely obese adolescents. The Journal of pediatrics, 157(2), pp.252-258.
- Volek, J.S., Phinney, S.D., Forsythe, C.E., Quann, E.E., Wood, R.J., Puglisi, M.J., Kraemer, W.J., Bibus, D.M., Fernandez, M.L. and Feinman, R.D., 2009. Carbohydrate restriction has a more favorable impact on the metabolic syndrome than a low fat diet. Lipids, 44(4), pp.297-309.
- Aude, Y.W., Agatston, A.S., Lopez-Jimenez, F., Lieberman, E.H., Almon, M., Hansen, M., Rojas, G., Lamas, G.A. and Hennekens, C.H., 2004. The national cholesterol education program diet vs a diet lower in carbohydrates and higher in protein and monounsaturated fat: a randomized trial. Archives of internal medicine, 164(19), pp.2141-2146.
- Daly, M.E., Paisey, R., Millward, B.A., Eccles, C., Williams, K., Hammersley, S., MacLeod, K.M. and Gale, T.J., 2006. Short‐term effects of severe dietary carbohydrate‐restriction advice in Type 2 diabetes—a randomized controlled trial. Diabetic Medicine, 23(1), pp.15-20.
- Brinkworth, G.D., Noakes, M., Buckley, J.D., Keogh, J.B. and Clifton, P.M., 2009. Long-term effects of a very-low-carbohydrate weight loss diet compared with an isocaloric low-fat diet after 12 mo. The American journal of clinical nutrition, 90(1), pp.23-32.
- Kempner, W., Newborg, B.C., Peschel, R.L. and Skyler, J.S., 1975. Treatment of massive obesity with rice/reduction diet program: an analysis of 106 patients with at least a 45-kg weight loss. Archives of internal medicine, 135(12), pp.1575-1584.
- Roberts, C.K., Won, D., Pruthi, S. and Barnard, R.J., 2006. Effect of a diet and exercise intervention on oxidative stress, inflammation and monocyte adhesion in diabetic men. Diabetes research and clinical practice, 73(3), pp.249-259.
- Kiehm, T.G., Anderson, J.W. and Ward, K., 1976. Beneficial effects of a high carbohydrate, high fiber diet on hyperglycemic diabetic men. The American journal of clinical nutrition, 29(8), pp.895-899.
- Roberts, C.K., Chen, A.K. and Barnard, R.J., 2007. Effect of a short-term diet and exercise intervention in youth on atherosclerotic risk factors. Atherosclerosis, 191(1), pp.98-106.
- Esselstyn Jr, C.B., Gendy, G., Doyle, J., Golubic, M. and Roizen, M.F., 2014. A way to reverse CAD?. Journal of Family Practice, 63(7), pp.356-364.
- Johnstone, A., 2015. Fasting for weight loss: an effective strategy or latest dieting trend?. International Journal of Obesity, 39(5).
- Zauner, C., Schneeweiss, B., Kranz, A., Madl, C., Ratheiser, K., Kramer, L., Roth, E., Schneider, B. and Lenz, K., 2000. Resting energy expenditure in short-term starvation is increased as a result of an increase in serum norepinephrine. The American journal of clinical nutrition, 71(6), pp.1511-1515.
- Johnson, J.B., Summer, W., Cutler, R.G., Martin, B., Hyun, D.H., Dixit, V.D., Pearson, M., Nassar, M., Tellejohan, R., Maudsley, S. and Carlson, O., 2007. Alternate day calorie restriction improves clinical findings and reduces markers of oxidative stress and inflammation in overweight adults with moderate asthma. Free Radical Biology and Medicine, 42(5), pp.665-674.
- Varady, K.A., Bhutani, S., Church, E.C. and Klempel, M.C., 2009. Short-term modified alternate-day fasting: a novel dietary strategy for weight loss and cardioprotection in obese adults. The American journal of clinical nutrition, 90(5), pp.1138-1143.
- de Azevedo, F.R., Ikeoka, D. and Caramelli, B., 2013. Effects of intermittent fasting on metabolism in men. Revista da Associação Médica Brasileira (English Edition), 59(2), pp.167-173.