I weigh 7.7 kg and eat just under 1,600 cals a day. Am I really going to lose weight!?

Maybe 77 kg and not 7.7??? You don't say how tall or old you are, so it's hard to know if you'll lose.

If you are correctly weighing your food on a digital food scale and weighing or measuring all liquids and sauces and have correct numbers--then yes you will lose weight if 1600 is the daily goal that MFP gave you. You will find that you can eat more if you up your vegetables, because they tend to be lower calorie. Good luck and hope you have success.

You should log any purposeful exercise and eat back at least some of those calories on top of your 1600. This is how MFP is designed. However, for strength / resistance training, it's likely that MFP will overestimate the calorie burn so maybe only eat 50-75%. After 6 weeks, you'll know whether you're losing at the selected rate or not.

Also, don't eat "under your calorie intake". MFP set your calories, based on the data you entered, to lose weight at a safe rate. You should be eating your 1600 a day, plus exercise calories.

And yes, you can eat and drink what you like as long as you're weighing it, selecting accurate database entries and eating the number of calories allocated to you. However, as weight loss may take months or even years, most people find it easier to stick to their target if they eat balanced meals that roughly fall in line with the macro settings that MFP defaults to.

I still eat chocolate, pastries etc. I just don't eat them every day. For the whole time I was losing weight (and now that I'm in maintenance) I've continued eating the same foods as before, but in smaller portions.

1600 may or may not be the right number for you; impossible to say given the info provided. Go to the MFP Goals tool tab. Enter your age, gender, height, weight, and your weight loss goal (e.g. 1 pound per week). It will tell you how many calories to eat. Eat that amount of calories, plus 1/2 or so of the calories for any intentional exercise (workouts) you do; in your case that'd be a couple hundred extra cals a few times per week.

Measure your food well, log everything, and dispense with cheat meals, off days, binge sessions, and all of that - that stuff will kill a diet. Just eat your MFP calorie allotment every day. The only sacrifice you have to make for this to work like a finely tuned sports car is to Not. Binge. Work within your MFP calories, every day or nearly every day. Make that MFP calorie target your North Star.

If you do that you will lose the weight. It's that simple. Millions of people have done it & it reliably works. You may come up 10 % short on the weight loss after six weeks, or be 10 % over the goal - there's some variability, but for most people not very much. Just plug away at it. Hit that calorie target everyday, lose the weight. Give it a full six weeks before questioning anything. It does take six weeks to be able to assess how things are going. After that, fine-tune.

Eat whatever you want. No rules as far as foods. None. Full cream in your coffee? No problem. I always use full cream and i don't eat any diet foods whatsoever - no "light" this or "low fat" that, no low-carb or no carb or reduced carb. Only real stuff. Today I had a big, fat roast beef and cheddar sandwich on an everything bagel with real mayo for brunch, some fruit and a granola bar for snack, and pasta in meat sauce with 4-Cheese Classico (my favorite) for dinner. For desert, I had 5 Hershey's kisses with almonds. Everything was precisely measured so I would hit my calorie target dead on, and it will be another glorious, easy day of weight loss. I cannot overemphasize how important it is to eat the foods you love and not to take all the good stuff away as though a diet should be a form of pennance. You are So. Much. More. Likely to succeed with weight loss if you eat the stuff you enjoy.

Weight loss is simple: hit that calorie number everyday and then STOP, and don't cheat. And you will lose allllllll the weight you want over time. Be patient and let those weeks start stacking up in the rear view mirror and you will be where you want to be before you know it.