Learn Portuguese (Portugal): Ninguém consegue emagrecer sem deixar de beber refrigerantes. - Nobody can lose weight without giving up soda.

The structure deixar de followed by an infinitive verb like beber means to stop or to quit doing something. Here, deixar de beber literally means to stop drinking, which translates naturally to giving up soda.

Why does the sentence use consegue for can instead of pode?

While the verb poder means can in the sense of having permission or possibility, conseguir means to manage to or to successfully achieve a result. Losing weight takes effort, so consegue emagrecer focuses on the ability to actually achieve it.

Why is the infinitive used in sem deixar rather than a gerund?

In Portuguese, whenever a verb directly follows a preposition like sem, it must always be in its dictionary form, called the infinitive. English often uses words ending in -ing after prepositions, but Portuguese does not.

Ninguém means nobody. Why is there no não to make the sentence negative?

If a negative word like ninguém appears before the verb in Portuguese, you do not add não. You only use a double negative when the negative word comes after the verb. Since ninguém starts this sentence, no extra negative word is needed.