Understanding Different Diets for Individuals with Obesity: Which Diet is the Best Suited for You?

Low-calorie diets are a common approach to weight management. They work by restricting caloric intake to induce a negative energy balance that leads to weight loss.

Generally, low-calorie diets provide between 800 and 1,500 calories per day. Multiple systematic reviews and meta-analyses have demonstrated that low-calorie diets are effective in inducing weight loss among individuals with obesity (2).

However, a significant limitation of low-calorie diets is their difficulty to maintain over the long-term due to the associated hunger and consequent food cravings that participants encounter.

This can make an individual feel deprived, hinder their chances of weight loss, and ultimately result in frustration and relapse.

Low-fat diets involve reducing the fat content of the diet to less than 30% of total caloric intake.

Such diets can help promote weight loss by restricting caloric intake while simultaneously removing high-fat foods known to be energy-dense but low in essential nutrients.

Several studies suggest that low-fat diets can promote weight loss, particularly in individuals with insulin resistance, and are effective in lowering total cholesterol and LDL-cholesterol levels (3,4).

Maintaining a healthy balance between energy intake and energy expenditure is the primary challenge of low-fat diets, as it can be out of balance because such diets often focus on carbohydrates to compensate for the reduced fat content, which can lead to an increased risk of insulin resistance.

Low-carbohydrate diets, also referred to as ketogenic diets or Atkins diets, are high-fat, low-carbohydrate diets that aim to induce a state of ketosis in the individual by promoting the breakdown of fat for energy.

Individuals who follow a low-carbohydrate diet typically consume less than 50 grams of carbohydrates per day.

Low-carbohydrate diets have been the subject of much debate in the scientific community for years, with some studies suggesting they may pose potential negative impacts on cardiovascular and metabolic health.

However, other studies demonstrate that low-carbohydrate diets can promote weight loss, lower blood sugar levels, reduce triglycerides, and increase levels of HDL cholesterol (5,6).

The Mediterranean diet is a healthy dietary pattern that emphasizes fresh whole foods, including vegetables, fruits, whole grains, legumes, fatty fish, and olive oil, with moderate consumption of dairy, nuts, and red wine.

The Mediterranean diet incorporates a balance of macronutrients but is high in healthy fats such as monounsaturated and polyunsaturated fats.

The Mediterranean diet has been shown to effectively reduce the risk of cardiovascular and metabolic diseases, including obesity (7,8).

Recent studies conducted by Sofi F, et al. found a significant association between the Mediterranean diet and its components with body weight, LDL and HDL-cholesterol levels, blood pressure, and blood glucose among overweight and obese adults (9,10).

Other diet types that have gained popularity recently include intermittent fasting, paleo diets, and plant-based diets.

Intermittent fasting involves reducing calorie intake in a time-restricted manner, while paleo diets emphasize the consumption of whole, unprocessed foods similar to what our Paleolithic ancestors consumed.

Plant-based diets emphasize fresh whole foods such as fruits, vegetables, grains, and legumes, which are high in fiber, vitamins, and minerals but contain no animal products.

Research findings regarding these diet types are still emerging, and further scientific investigation is required to determine their real impact on metabolic and cardiovascular health outcomes.

Choosing the right diet for individuals with obesity is a complex decision that should be informed by multiple factors.

These include an individual's preferences in terms of food choices, cultural background, health status, and lifestyle behaviors.

However, many experts recommend that individuals with obesity should seek guidance from a healthcare provider and/or a registered dietitian before committing to a diet plan.

Nutritional counseling is essential to set realistic expectations, help with meal planning, and improve adherence to the chosen diet plan.

There is no one-size-fits-all approach when it comes to effective diets for individuals with obesity.

Each diet has its own benefits and drawbacks. Low-calorie diets can offer short-term results but can be challenging to maintain over the long term.

Low-fat diets are good for promoting cardiovascular health but can lead to insulin resistance and weight gain. Low-carbohydrate diets have been shown to induce weight loss, but some concerns have been raised regarding long-term safety.

The Mediterranean diet is healthy overall but may not be particularly effective for weight loss if not accompanied by a caloric deficit. Ultimately, choosing the right diet for individuals with obesity depends on key factors such as personal preferences, cultural background, lifestyle behaviors, and overall health status.

The advice of a qualified health professional or registered dietitian can help individuals with obesity make informed decisions before committing to a specific diet strategy.

Sources

1. World Health Organization (WHO). Obesity and overweight.
2. Sacks FM, Bray GA, Carey VJ, et al. Comparison of weight-loss diets with different compositions of fat, protein, and carbohydrates. N Engl J Med. 2009;360(9):859-873.
3. Gardner CD, Kiazand A, Alhassan S, 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;297(9):969-977.
4. Djoussé L, Petrone AB, Gaziano JM. Consumption of fried foods and risk of coronary heart disease: Spanish cohort of the European Prospective Investigation into Cancer and Nutrition study. BMJ. 2012;344:e363.
5. Volek JS, Sharman MJ, Forsythe CE. Modification of lipoproteins by very low-carbohydrate diets. J Nutr. 2005;135(6):1339-1342. 
6. Noakes M, Keogh JB, Foster PR, Clifton PM. Effect of an energy-restricted, high-protein, low-fat diet relative to a conventional high-carbohydrate, low-fat diet on weight loss, body composition, nutritional status, and markers of cardiovascular health in obese women. Am J Clin Nutr. 2005;81(6):1298-1306.
7. Estruch R, Ros E, Salas-Salvadó J, et al. Primary prevention of cardiovascular disease with a Mediterranean diet. N Engl J Med. 2013;368(14):1279-1290.
8. Tosti V, Bertozzi B, Fontana L. Health benefits of the Mediterranean diet: metabolic and molecular mechanisms. J Gerontol A Biol Sci Med Sci. 2018;73(3):318-326.
9. Sofi F, Cesari F, Abbate R, et al. Adherence to Mediterranean diet and health status: meta-analysis. BMJ. 2008;337:a1344.
10. Sofi F, Macchi C, Abbate R, Gensini GF, Casini A. Mediterranean diet and health status: an updated