A shocking watch for park goers. ABS-CBN News

Cows, pigs and sheep tortured before their slaughter. Monkeys and mice undergoing medical experiments. Fish skinned alive. Chicks still conscious as they are sent to the meat grinder.

These scenes flashed Saturday on TV screens carried by protesters at the Quezon Memorial Circle pushing for veganism, the rejection of all animal-based products.

Sporting Guy Fawkes masks, the activists who call themselves Anonymous for the Voiceless stood in a square beside the park's fountain, in a formation they dubbed "cube of truth."

There were no loudspeakers or chants. The masked protesters were silent during 3-hour demonstration.

The demonstration lasted into the night. ABS-CBN News

Other members of the group explained to curious park-goers that these practices were happening all around the world.

"Animals don't have voices, which is why we are the ones who are shouting for them--'Do not eat animals,'" said activist Dan Angeles.

Angeles, 71, is the eldest member of the group's Metro Manila-based chapter.

He credits veganism for his vigor, saying it was spurred by a sibling's recovery from diseases after trying a vegan lifestyle.

Dan Angeles has been a vegan for 5 and a half years. ABS-CBN News

"I have no maintenance medication. I have no health issues. I am strong," he said.

Angeles said he walks 12 to 15 kilometers for exercise everyday.

"I now tend to hang out with younger people rather than those my age," he said. "I can even beat some of these kids at staying up late."

One of those "kids" is Buwi Comia, 30, who was an animal welfare advocate and had rescued pets, before he tried veganism to lose weight some 2 years ago.

He said he later made a full commitment to veganism after seeing videos of cruelty to animals.

Comia said his weight has gone down to 69 kilos from 120 kilos after going vegan.

Before & After: Buwi Comia, one of the animal rights activists, credits his loss in weight from 120 to 69 kilos to his switch to veganism 2 years ago. pic.twitter.com/GIm04cidJq — Anjo Bagaoisan (@anjo_bagaoisan) November 3, 2018

"I really do it for the animals, but I think my weight loss and increase in self-confidence today is just a bonus of my switching to veganism," Comia said.

Angeles said he is often asked about where vegans get their protein after cutting out meat.

He said he makes his own milk from plant-based products such as nuts and grains.

Protein substitutes like tofu and "faux meat" are also becoming more available in the market, said other members of the group, adding that the public may visit their website for more information.

Comia said vegans don't need to cut down on the amount they eat since plant-based food have lower calories.

"Losing weight is not about eating less, it's about eating the right food," he said.

One of the organizers, who goes by the moniker Egg Purity, said the group's "shock and talk" action is effective in getting people's attention.

The "cube of truth" event was mounted by other animal rights activists in 382 cities worldwide on the same day.

This is their second time to do it in the Philippines.

"Many said they wanted to become vegan for their health and for the environment," Egg Purity said.

For Comia, their advocacy does not claim that those who have switched to veganism are more morally upright than those who have not, but rather only raises awareness for the rights of animals who have no voice.