Since this friend is also a medical doctor we didn't need to go into the many ills associated with aspartame use, including neurological disorders and paradoxical weight gain, or with the added phosphorus which can lead to weakened bones and kidney stones.
So I told him to drink more water, but said friend drinks no water. He can't stand the taste of it. Weird, since water has no taste. So I suggested he eat fruit. Which he said he could try. He has a huge sweet tooth and his diet includes several chocolate bars a day (in addition to the red meat and refined bread he normally eats for dinner).
I took him to the store and we bought melons and bananas and berries. I taught him how to make smoothies. A week later he came to me saying he had ditched the diet coke habit altogether, but was having 5 liter-size smoothies a day, including 15 bananas, a couple pounds of berries, and an equal amount of watermelon.
"Good for you," I said.
"But I have gained 10 pounds!" he vociferated.
I asked him what else he'd been eating. "The usual" was his reply. "Mostly fruit during the day and my usual dinner of lamb chops and baked potatoes."
I thought for sure he was missing something. "What about those days you are in class from 9 to 3. Surely you aren't making smoothies."
"Um," was his rejoinder.
"Create a food log," I suggested. I did the math. Fifteen bananas and a couple pounds each of berries and melon is 2500 calories a day. Added to a 1,000 calorie meal is 3,500 calories a day, which he was probably burning off, since he's an active sort who likes to play basketball and hike. Even if such an intake provided an excess of 500 calories a day, this would add to a pound of weight gain, not the 10 he said he'd put on. I thought to myself that my friend had likely been visiting the snack machine at the hospital and eating more than the roast beef sandwich he said he'd had for lunch.
Not all of us are good at recalling what we eat because we eat unconsciously, stuffing food in our mouths while talking or reading or watching TV. In other words, few of us actually watch what we eat. Some of us do, however. Take Chloe Sevigny. The actress and style icon has always been thin. Although remembering her breakthrough role in the movie Kids she looks back and calls herself fat, saying she had been living off burritos in San Francisco back in the day.
She clearly wasn't fat. She's her own worst critic. But she sure has a good memory, considering the movie was made 20 years ago.
So until you are that skilled at remembering what you eat and when, keep a log. After only a few days you will train yourself to watch exactly what you eat, and not to eat mindlessly. Then it will become reflexive and you can ditch the diary.
A final word on my friend. What I didn't tell him is that the soluble fiber he was ingesting with all those bananas and fruits can absorb 10 times its weight in fiber, which is great to bulk up the stool and lower cholesterol, but can give the false impression that you are gaining weight.
And while we are on the subject of fiber, it seems scientists are adding new benefits by the day to this indigestible product of plants. Have you heard this? A certain type of bacteria, called Faecalibacterium prausnitzii, which is a type of beneficial bacteria of the gut, feed off this fiber and produce anti-inflammatories which ward off conditions such as colitis and auto-immune diseases. By contrast, Bilophila wadsworthia, a species of bacterium linked to inflammatory bowel disease, bloomed in the microbiota of human volunteers fed a high-fat, high-protein diet in a recent experiment. So if you're on the Paleo kick and you value your health, get off it.
Many follow a high-protein low-carb approach in the interest of weight loss. But new research in the microbiome (bacteria of the gut) has turned this notion on its head. Patients with higher levels of fiber-fermenting bacteria are noted for being thinner than those whose gut flora are made up of other types, making one's bacterial make-up, which is dependent on fiber intake, a determinant of body mass.
Now I should go tell that to my friend lest he go back to diet coke.