Searching for the ‘Holy Grail’ of Diets

Statistics survey 10,085 participants in the USA between July 2023 and June 2024 regarding the diets or nutritional guidelines they follow.

• 52% do not follow any dietary rules.
• 17% follow low-carb or no-carb diets.
• 11% avoid dairy products or products containing lactose.

Of course, we don’t know what motivates these choices. Did they arise from health conditions (such as lactose intolerance), weight loss efforts, or a desire for a healthier lifestyle?

Research of an online survey of 1,005 Americans published by the International Food Information Council (IFIC) in 2022, found:

• 52% of Americans reported following a diet or eating pattern in the past year, a significant increase compared to previous years.
• The most popular diets were clean eating (16%), mindful eating (14%), calorie counting (13%), and a plant-based diet (12%), with low-carb in seventh place (6% ).
• The main motivations were long-term health protection (35%), weight loss (34%), and feeling better and more energy (31%).

Based on these two surveys, we could come to the conclusion that there is a great interest in diets and nutrition from the general public, and that there is a significant difference in the types of diets that people follow. While the Statista survey emphasized low-carb diets, the IFIC survey emphasized clean eating.

The public, without expertise, turn to sources such as Dr. Google for information, which may lead to questionable quality information based on the website or influencer.

Diets: There’s No Shortage of Choices

We can define a diet as a regimen or plan designed for a specific person, taking into account their goals as well as unique physical, socioeconomic and cultural characteristics. Although this definition is simple, identifying the “best” nutritional strategy among the many options available can be challenging without professional help.

For example, US News Health published its classification of 30 different diets as the The Best Diets in 2024. Among their criteria:

• Nutrient integrity
• Health risks and benefits
• Long term sustainability
• Evidence-based effectiveness
• The strengths and weaknesses of each diet
• Specific purposes that each diet could fulfill more effectively

The top three “overall” diets included the Mediterranean diet (rich in vegetables, whole grains, olive oil, fish, and minimal red meat), the DASH diet (similar to the Mediterranean diet but with a higher sodium intake low), and the MIND diet. (a combination of the Mediterranean and DASH diets aimed at preventing cognitive decline).

Although this ranking reflects the opinions of experts, it is not positive scientific evidence of the healthiest diet.

Which Diet Is Healthiest?

Given the Mediterranean diet’s reputation as the “best overall diet” and its frequent praise in news reports for its health benefits, a systematic review and meta-analysis is particularly useful in addressing this question. .

Published in the British Medical Journal in 2023, this review It aimed to determine the relative effectiveness of structured diet programs and healthy behavior programs in preventing mortality and major cardiovascular events (MACE) in patients at increased risk of cardiovascular disease.

The analysis included only randomized clinical trials with a minimum of nine months of intervention in adults with cardiovascular disease or two risk factors that compared a structured nutrition program and reported MACE. These structured nutrition programs may include non-nutritional interventions, such as exercise, psychosocial support, or behavioral support, as well as smoking cessation and drug treatments.

In total, 40 studies were considered adequate, involving 35,548 participants. The mean follow-up period was three years. [1] Diet programs included:

• 18 studies adopting a low-fat diet program
• 6 studies using a very low fat diet program
• 4 studies used a combination of low-fat and low-sodium diets
• Followed 6 modified fat diet studies
• 12 studies used the Mediterranean diet
• 3 studies used the Ornish diet, essentially a plant-based diet
• 1 study used the Pritikin diet, emphasizing unprocessed foods

The quality of studies examining the individual the effect of diet for low-fat and Mediterranean diet programs was reduced by co-interventions and in two studies that had indirect estimates of their effect.

• Evidence showed that the Mediterranean diet program was superior to minimal intervention in reducing all-cause mortality. Participants who followed the diet were 28% less likely to die. That benefit increased as the patient’s risk increased.
• The Mediterranean diet was also superior in reducing cardiovascular mortality, non-fatal myocardial infarction, and stroke.

• The evidence showed that the low-fat diet program was superior to “minimal intervention” in reducing all-cause mortality. Participants who followed this diet were 16% less likely to die from any cause. This diet was the only one that reduced the frequency of unplanned cardiovascular interventions.
• The combined low-fat, low-sodium diets show benefits in reducing stroke risk in high-risk patients.

• When controlling for covariates such as physical exercise, support in stress management, smoking cessation, and medication treatment, there were no significant differences in diet results.

The authors conclude that nutritional programs that combine moderate and low-fat diets – with physical exercise or no other intervention – can reduce all-cause mortality and non-fatal myocardial infarction in elderly patients at increased cardiovascular risk. However, there is no convincing evidence that the Mediterranean diet is better than the low-fat diet in preventing these outcomes.

However, before increasing your intake of olive oil, omega-3-rich fish, and reducing whole grains and red meat consumption, which is still good advice, it is important to acknowledge that there were some significant limitations with the study.

The main limitation of this review is the inclusion of dietary programs with concomitant interventions, such as drug treatment and smoking cessation, which makes it difficult to identify the actual role of diets in the observed results. Providing these joint interventions to both the control and intervention groups would reduce the risk of bias. In addition, the researchers emphasize the difficulty of analyzing adherence to nutritional programs.

Conclusive, Conclusive Conclusion

Based on the evidence presented in the review and its limitations, the question of which diet is the healthiest remains open. Although this may sound disappointing, it is the most realistic.

What can be understood is that a balanced and structured diet based on generally healthy foods is likely to be more effective than doing nothing or doing very little when considering healthy options. However, the exact composition of such a diet requires further exploration, not to mention personalizing it to your needs.

Ultimately, the review is in line with common sense: healthy eating is only one component of a healthy lifestyle. A lifestyle including physical exercise, stress reduction, smoking cessation, and, when necessary, drug treatment, all actions that reduce mortality and cardiovascular risks – which is pretty obvious, by the way.

[1] Regarding methodological quality, 13 studies were classified as having a low risk of bias, and 27 studies were classified as having a high risk.

Source: Comparison of seven popular structured nutrition programs and risk of mortality and major cardiovascular events in patients at increased cardiovascular risk: a systematic review and network meta-analysis. BMJ DOI: 10.1136/bmj-2022-072003.