Yes, vegetable cellulose is keto-friendly. In the context of a ketogenic diet, which is low in carbohydrates and high in fats, cellulose, a form of fiber found in vegetables, doesn't get digested or absorbed by the human body. Instead, it passes through the digestive system, aiding in digestion and helping to maintain bowel health without contributing net carbs. Therefore, consuming products with vegetable cellulose can be beneficial for those on a keto diet looking to meet their fiber needs without increasing their carb intake. This makes vegetable cellulose a suitable component for keto dieters who often need to find ways to incorporate fiber into their low-carb regimen.

The amino acids leucine and lysine are considered purely ketogenic. In metabolism, amino acids can be classified based on their catabolic pathways into glucogenic, ketogenic, or both. Glucogenic amino acids can be converted into glucose via gluconeogenesis, while ketogenic amino acids are metabolized into ketone bodies. Leucine and lysine are unique because they are the only amino acids that solely yield acetyl-CoA or acetoacetyl-CoA, without generating any substrates for gluconeogenesis, thus termed purely ketogenic. This property is particularly relevant in metabolic states like fasting, where ketone bodies become a major energy source for tissues like the brain that are usually glucose-dependent.

As of my last update in 2023, there's no global consensus on banning polypropylene (PP) packaging outright. Polypropylene, a type of plastic, is widely used due to its versatility, resilience, and recyclability. However, the environmental impact of single-use plastics has led to increased scrutiny and regulatory action in various regions. Countries and local jurisdictions may implement regulations that restrict the use of certain types of plastic packaging, including PP, especially where alternatives are viable and sustainable. The European Union, for instance, has been at the forefront of such initiatives, targeting a wide range of single-use plastic products. The direction of future policies might hinge on advancements in recycling technologies, development of biodegradable alternatives, and public pressure for more sustainable packaging solutions. Whether PP packaging will face a ban depends on these factors, alongside international efforts to tackle plastic pollution.