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The good thing about paleo is that you can eat a broad range of foods. An advantage that makes paleo versatile and tasty enough to adhere to.

I know that I will probably have annoyed some of you by implicitly calling "paleo" non-scientific. If we are honest, though, the whole paleo concept is based on extrapolating data from modern hunter gatherer populations, infusing them with a minimal amount of real evidence of what our ancestors ate and mixing that with the intrinsically flawed assumption that the way our ancestors ate (which was 100% opportunistic and 0% "optimized") was the optimal way for us to eat... and no, I am not going to apologize for what some of you may consider an assault on respected scientists who have published more than a dozen of papers which constitute the theoretical backbone of an experimentally still mostly unverified, but promising approach to "healthy dieting".
Just to make sure there's no confusion. I am not saying that everything that Eaton, Cordain and others wrote is bogus. I am just saying that their papers are above everything else the material based on which others have formulated research hypothesis and done experimental research. Research that has been reviewed in a soon-to-be-published paper in the influential American Journal of Clinical Nutrition, by Eric W Manheimer, Esther J van Zuuren, Zbys Fedorowicz, and Hanno Pijl. A paper that leaves its readers with a generally positive conclusion, but state that "[t]he available data warrant additional evaluations of the health benefits of Paleolithic nutrition" (Manheimer. 2015). Now that does not sound like much, but in view of the scarcity of evidence it is more than you'd usually expect from a review that was partly financed by the National Center for Complementary and Alternative Medicine of the US.

When they decided on the methodology, inclusion and exclusion criteria, Manheimer et al. began with the simple, but important question "Does paleo-nutrition improve risk factors for chronic disease more than other dietary interventions in people with the metabolic syndrome?" To answer this question, the authors searched the following bibliographic databases for reports of controlled trials without any language restriction (likewise included were relevant results from the following ongoing trials databases):

• Figure 1: Details of the selection process in January 2015 (Manheimer. 2015).

  The Cochrane Central Register of Controlled Trials (CENTRAL) 2014
• MEDLINE via OVID (from 1946)
• EMBASE via OVID (from 1974)
• LILACS (Latin American and Caribbean Health Science Information database, from 1982)
• Science Citation Index (from 1988 to the present).
• The metaRegister of Controlled Trials 
• The U.S. National Institutes of Health Ongoing Trials Register
• The Australian and New Zealand Clinical Trials Registry 
• The World Health Organization International Clinical Trials Registry platform 

The reference lists of all identified RCTs and key review articles were also reviewed and squared with the following selection criteria:

"Randomised controlled trials will be included. Any other study design will be excluded. We will only include cross-over trials if we are able to extract the relevant data from the first phase (i.e., before the crossover occurred) because we consider the risk for carryover effects to be prohibitive" (Manheimer. 2015).

In addition, the scientists looked for dietary interventions which were designed to emulate as much as possible, for the modern time, the diet of plants and animals eaten by human beings during the Paleolithic era. More precisely, Manheimer et al. included only studies with diets with...

• large amounts of vegetables (including root vegetables), 
• fruits (including fruit oils e.g., olive oil, coconut oil, palm oil), 
• nuts, fish, meat, and eggs

To make sure to get relevant data, the duration of the dietary intervention had to be at least one week. Studies showing only acute improvement in blood pressure, glucose levels or whatever from eating more veggies and fruit and calling that "the paleo diet" were thus not included in the meta-analysis. The same goes for two uncontrolled clinical trials, as well as all studies where the dietary protocols included one or several of the following "paleo-nono-foods": dairy, grain-based foods, legumes, extra sugar, nutritional products of industry (including refined fats, refined carbohydrates).
The number of studies all these search efforts brought to light was - as you, as someone who's heard about all the pertinent trials on www.facebook.com/waredownloadsoft, already, will know - not exactly extensive. All in all, only four RCTs that involved 159 participants were included. This were four RCTs with very similar results, as the researchers' meta-analysis revealed:

"In this systematic review and meta-analysis of 4 RCTs, Paleolithic nutrition resulted in greater short-term pooled improvementson each of the 5 components of the metabolic syndrome than did currently recommended guideline-based control diets. However, the greater pooled improvements did not reach significance for 2 of the 5 components (i.e., HDL cholesterol and fasting blood sugar). For each metabolic syndrome component, the quality of the evidence for the pooled estimate for improvement was moderate" (Manheimer. 2015).

I guess what these results mean is much easier to grasp if you take a look at the plot of the data I've created for you. Keep in mind: What you see in Figure 1 are the differences compared to the allegedly "optimal" recommended diets in the respective studies, not differences to the habitual diets of the subjects which were probably significantly more pronounced.

Figure 2: Improvements in  triglycerides, HDL, fasting blood sugar, waist circumference, systolic and diastolic blood pressure with "paleo" diets vs. nationally recommended diets (Manheimer. 2015).

The most significant and probably practically relevant benefits of the paleo diet can be seen in the graph on the right hand side: Compared to the relatively small (and practically probably almost irrelevant, if not already stat. non-significant) advantages in terms of blood lipids and glucose, the improvements in blood pressure and waist circumferences are what I would use to argue in favor of paleo-esque dietary recommendations in front of any expert panel.
After all, more than 50 million people in the US alone are suffering from full-blown hypertension (high blood pressure). In view of the fact that even pre-hypertension is associated with an 80% increased risk of cardiovascular morbidity (learn more), the consumption of a paleo-esque diet could thus save the lives of millions of people. In view of the fact that this would also save us billions of dollars that are spent on managing hypertension every year, this is probably the strongest argument in favor of the "paleo diet" (Note: It's not an exclusive advantage, though. The DASH diet with a similar if not higher vegetable and fruit content has similar effects).

Figure 3: Increase in all-cause mortality risk among 48 500 men and 56 343 women, 50 years or older, in the Cancer Prevention Study II Nutrition Cohort according to BMI and waist circumference (Jacobs. 2010).

A bit less convincing for the average panel member, but practically as relevant are the significant decreases in waist circumference. With studies showing a 2-fold elevated all-cause mortality risk in average American men and women with WC ≥120 cm (compared with <90 cm) and WC ≥110 cm (compared with <75 cm), respectively (see Figure 3 for details), there's yet little doubt that an improvement in this often overlooked health-marker is just as important as the reduction in blood pressure.
References:

• Boers, Inge, et al. "Favourable effects of consuming a Palaeolithic-type diet on characteristics of the metabolic syndrome: a randomized controlled pilot-study." Lipids Health Dis 13.1 (2014): 160. 
• Eaton, S. Bovn, M. Konner, and N. Paleolithic. "A consideration of its nature and current implications." N Engl j Med 312.5 (1985): 283-9.
• Jacobs, Eric J., et al. "Waist circumference and all-cause mortality in a large US cohort." Archives of internal medicine 170.15 (2010): 1293-1301.
• Jönsson, Tommy, et al. "Beneficial effects of a Paleolithic diet on cardiovascular risk factors in type 2 diabetes: a randomized cross-over pilot study." Cardiovasc Diabetol 8.35 (2009): 1-14.
• Lindeberg, Staffan, et al. "A Palaeolithic diet improves glucose tolerance more than a Mediterranean-like diet in individuals with ischaemic heart disease." Diabetologia 50.9 (2007): 1795-1807.
• Manheimer, et al. "Paleolithic nutrition for metabolic syndrome: systematic review and meta-analysis." American Journal of Clinical Nutrition (2015): Ahead of print.
• Mellberg, Caroline, et al. "Long-term effects of a Palaeolithic-type diet in obese postmenopausal women: a 2-year randomized trial." European journal of clinical nutrition 68.3 (2014): 350-357.

I guess if someone finally dared to do this study, there would be a linear or exponential association between the number of processing steps red meat has undergone and the increase in cancer risk from regular consumption. Stay away from cheap bacon, sausages & co.

The potential relationship between red meat consumption and colorectal cancer (CRC) has been the subject of scientific debate. In fact, you will remember that I have addressed the issue repeatedly and in various articles. If you read all or at least some of the articles you will also be aware of the fact that the evidence against red meat is of observational nature and has a high degree of resulting uncertainty.

Dominik D. Alexander's and his colleagues's objective was thus to conduct a systematic quantitative assessment of the epidemiologic literature. Specifically, they updated and expanded their previous meta-analysis by integrating data from new prospective cohort studies and conducting a broader evaluation of the relative risk estimates by specific intake categories.
Data from 27 independent prospective cohort studies were meta-analyzed using random-effects models, and sources of potential heterogeneity were examined through subgroup and sensitivity analyses. In addition, a comprehensive evaluation of potential dose-response patterns was conducted.

Table 1: Meta-analysis of prospective studies of red meat consumption and colorectal cancer (Alexander. 2015)

In the meta-analysis of all cohorts, a weakly elevated summary relative risk was observed (1.11, 95% CI: 1.03–1.19); however, statistically significant heterogeneity was present. Furthermore

However, in the model that included studies of fresh red meat (n D 17 studies independent of processed meat items), the SRRE dropped to 1.05 and was no longer statistically significant (95% CI: 0.98–1.12), and the model was less heterogeneous (p-H D 0.328). Of 13 of these studies that explicitly defined red meat, the SRRE was 1.04 (95% CI: 0.98–1.14, p-H D 0.263). [...] Stronger (and more heterogeneous) associations were observed in meta-analyses of studies conducted in North America (SRRE D 1.18, 95% CI: 1.05–1.32), compared with studies published in other countries (SRRE D 1.07, 95% CI: 0.98–1.16). The model of studies conducted in China and Japan had the weakest SRRE (1.01, 95% CI: 0.92–1.12; Chen et al. and Khan et al. excluded). Interestingly, the summary associations were modified by publication date, with the SRREs becoming monotonically weaker over time. For example, meta-analysis of 8 studies published prior to the year 2000 resulted in an SRRE of 1.30 (95% CI: 1.06–1.59), while the SRRE for the studies published in the past 5 years was 1.09 (95% CI: 0.98–1.21)" (Alexander. 2015).

So, if sub-analysis using models that looked for the isolated effects of fresh red meat (from processed meat), adjusted for more relevant factors, analyzed women only, and were conducted in countries outside of the United States showed once again that the allegedly "deadly" association between "red meat" and cancer is in fact one between the bacon, burger and overall junkfood laden diet the average American still considers "food", what's the conclusion then? Right, it's the same conclusion researchers have drawn based on the 2007 World Cancer Research Fund Report:

"One of the 10 universal guidelines for healthy nutrition in a report of the World Cancer Research Fund released at the end of 2007 is to “limit intake of red meat and avoid processed meat”, as a result of the “convincing evidence” for an association with an increased risk of colorectal cancer development" (Demeyer. 2008). 

In addition Daniël Demeyer, Karl Honikel, and Stefaan De Smet rightly demand that the food industry takes steps to develop "improved processed meats using new ingredients" by omitting or lowering the use of nitrite and nitrate (a real problem for bacon and sausages), reducing the exuberant salt content and taking measures to inhibit the damaging nitros(yl)ation reactions by haem and nitrite/nitrate present in the digestive tract and of the ensuing carcinogenic effects.

Table 2: Relative risk (RR)* of colorectal cancer in relation to animal food cooking method | all number > 1.00 indicate an increased risk, all number < 1.00 indicate a decreased risk (Lee. 2005).

In the end, all the efforts of the industry will yet be in vain, if you keep buying high nitrite bacon, and deep frying previously benign fresh meats to turn them into colorectal and cancer promoting agents (Lee. 2009 | note: Stir-fried meats are not associated with increased cancer risk in the same study).
References:

• Alexander, Dominik D., et al. "Red Meat and Colorectal Cancer: A Quantitative Update on the State of the Epidemiologic Science." Journal of the American College of Nutrition ahead-of-print (2015): 1-23.
• Chen, Kun, et al. "Nested case-control study on the risk factors of colorectal cancer." World Journal of Gastroenterology 9.1 (2003): 99-103.
• Demeyer, Daniël, Karl Honikel, and Stefaan De Smet. "The World Cancer Research Fund report 2007: A challenge for the meat processing industry." Meat science 80.4 (2008): 953-959.
• Khan, M. M. H., et al. "Dietary habits and cancer mortality among middle aged and older Japanese living in hokkaido, Japan by cancer sites and sex." Asian Pacific Journal of Cancer Prevention 5.1 (2004): 58-65.
• Lee, Sang-Ah, et al. "Animal origin foods and colorectal cancer risk: a report from the Shanghai Women's Health Study." Nutrition and cancer 61.2 (2009): 194-205.