Many breastfeeding mothers wonder if it's OK to take caffeine. In fact, many nursing mothers just avoid caffeine in case it would keep their babies fussy, jittery and awake.
The answer is yes, you can take caffeine while breastfeeding, as long as you don't go over about 300 mg a day.
It's an important question because caffeine is in so many products, and taking coffee, tea, or soda is such a common ritual.
And breastfeeding mothers may be tempted to take caffeinated products because they are deprived of sleep by their newborns' odd sleep schedule.
Does caffeine enter breast milk?
Caffeine does enter the breast milk, yes, but not much of it at all. Some scientists gave nursing mothers caffeine in various amounts and then measured how much caffeine was in their breast milk.
A study of 145 mothers published in the Korean Journal of Pediatrics found :
Although caffeine is transferred to breast milk, the amount of caffeine transferred to breast milk is generally less than 1% of the amount consumed by the mother, and modest caffeine use does not negatively affect infants. Because no caffeine has been detected in an infant's urine with maternal consumption of up to three cups of coffee a day, it is unlikely that infants experience measurable exposure to caffeine. However, if a mother consumes more caffeine in one day than is found in 5 cups of coffee (750 mL), caffeine could begin accumulating in an infant's system, causing symptoms of caffeine stimulation.
Another study  found that only tiny amounts of caffeine were present in the breast milk of women who had ingested 750 mg of the stimulant.
But medical experts say an adult should have no more than 400 mg of caffeine in a day to avoid unwanted side effects. And an article on the Healthline website recommends no more than 300 mg for nursing women. The article states:
You can safely have up to 300 mg of caffeine per day — or the equivalent of two to three cups (470–710 ml) of coffee. Based on current research, consuming caffeine within this limit while breastfeeding does not cause harm to infants. 
How much caffeine passes to the baby?
A study of 15 lactating women published in the journal Pediatricsmeasured the amount of caffeine in their breast milk. The women consumed between 36 and 335 mg of caffeine, and had .06 to 1.5% of that amount in their milk. 
The Centers for Disease Control says preterm and newborn infants process caffeine more slowly than older babies. So even small amounts can build up over time in newborns.
Infants' bodies hold caffeine for 65 to 130 hours, as compared to the three to seven hours for adults. Infants' livers and kidneys are not fully developed, so the caffeine does not flush right away.
The video advises to stay under 300 mg of caffeine per day while breastfeeding.
How about pregnant women?
Recent news about caffeine, pregnancy and miscarriage is kind of confusing.
A complex study from the National Institutes of Health and Ohio State University linked couple’s consumption of more than two caffeinated beverages a day to a risk of miscarriage.
So, just to be safe, women trying to conceive and pregnant women should limit caffeine intake.
Don’t be fooled by the scary reports that drinking caffeine before conception causes miscarriages. There is zero evidence to suggest that women (or men, for that matter) need to give up caffeine before or while they’re expecting. If caffeine and miscarriages are causally related—and that’s still a big if—then the risk seems to apply only to women who drink more than two caffeinated drinks per day. If you want to be extra cautious while you’re expecting or trying to conceive, sure, forgo some of the caffeine you might normally have.
Just to be safe, The American Pregnancy Association states: “Due to conflicting conclusions from numerous studies, the March of Dimes states that until more conclusive studies are done, pregnant women should limit caffeine intake to less than 200 mg per day. This is equal to about one 12 oz cup of coffee.”
Try Viter Energy Mints or Gum
If you want to avoid filling up on liquids but still want your dose of caffeine, try Viter Energy Mints or Gum [5, 6]. Both contain moderate amounts of caffeine, and they will keep you from running to the bathroom all the time. They also have invigorating B vitamins and natural mint flavor to freshen your breath.
The mints have 40 mg of caffeine, and the gum has 60 mg. So five or six pieces spread throughout the day will have you microdosing instead of taking big does of caffeine just in the morning.
Viter Energy blog has a posting titled "Caffeine Microdosing: What Is It and Should You Try it?" 
According to dietitian Melissa Meier, caffeine microdosing involves consuming tiny amounts of caffeine throughout the day.
“Caffeine is a stimulant drug and in the right dose it can make you feel alert, but overdoing it can leave you feeling anxious, cranky, and tired,” she says.
To achieve the optimal dose of caffeine, consume somewhere between the 60 mg and 100 mg range. This is equivalent to:
Erectile dysfunction. In combination, those are two of the ugliest words known to man. But can caffeine help you get it up?
Science hasn't found the definitive answer to this question, but one study concluded that fewer men who consume caffeine have problems performing. The study said:
Caffeine intake reduced the odds of prevalent ED, especially an intake equivalent to approximately 2-3 daily cups of coffee (170-375 mg/day). This reduction was also observed among overweight/obese and hypertensive, but not among diabetic men. Yet, these associations are warranted to be investigated in prospective studies
Chewing gum to lose weight may be a viable method for some people, scientific studies have shown. It works in part by controlling appetite.
A study published in the scientific journal Appetite concluded:
"Overall, chewing gum for at least 45 min significantly suppressed rated hunger, appetite and cravings for snacks and promoted fullness (p<0.05). This study demonstrated some benefit of chewing gum which could be of utility to those seeking an aid to appetite control."